LOG NUMBER	PROPOSED SECTION AND TITLE/DESCRIPTION	ECONOMIC IMPACT
21-GP2-065	R403.13 Heat pump space heating. Table R405.4.2(1) Specifications for the standard reference and proposed designs. R503.1.2 Heating and cooling systems. This requires that space heating be provided by a heat pump—either gas or electric—as a method to reduce greenhouse gas emissions and save energy. There are exceptions provided for dwellings with small heating loads and allowances for supplementary heating following the requirements of Section R403.1.2. Replacement heating equipment is not required to comply with the heat pump requirement as long as it does not exceed the heating capacity of the equipment being replaced.	Cost: Estimated at $2,725 per dwelling unit or $1.14 per square foot. Energy Savings: Estimated annual energy savings of 3.85 kWh per dwelling or 5.5 kBTU per square foot.
21-GP2-066	R403.5.7 Heat pump water heating. R403.5.7.1 Supplementary heat for heat pump water heating systems. Table R405.4.2(1) Specifications for the standard reference and proposed design. R503.1.3 Service hot water systems. This requires that service water heaters in single family dwellings, duplexes and townhouses be provided by heat pump water heaters. Exceptions are provided for small water heaters, small dwelling units, supplemental water heating systems, and some renewable energy systems. This includes allowances for both gas and electric heat pump water heaters. Replacement water heating equipment is not required to comply with the heat pump requirement as long as it does not exceed the heating capacity of the equipment being replaced.	Cost: Estimated cost of $646 per dwelling or $0.27 per square foot. Energy Savings: 2.3 kWh or 3.2 kBTU per square foot.
21-GP2-084	R202 Definition "Residential building." R401.1 Scope. This definition change alters the scope of the Washington State Energy Code, Residential Provisions to resemble more closely that of the International Residential Code. Multifamily buildings with dwellings directly accessed from the outdoors will remain in the residential provisions, but other R-2 buildings are moved under the commercial provisions.	The proponent deemed that this would most likely be cost neutral. In some cases, there would be a cost savings for the buildings constructed under the commercial code, between the decreased envelope insulation requirements and the additional energy efficiency credits required for that code. There would be some education costs.
21-GP2-079	Table R402.1.2/R402.1.3 Insulation and fenestration requirements by component. This proposal changes the fenestration U-factor from 0.30 to 0.28 in both tables.	Cost: Estimated cost of about $400 per dwelling unit Energy Savings: Estimated at 389 kBtu per dwelling or 0.18 kBtu per square foot
21-GP2-073	Table R406.2 Fuel normalization credits. There are two options being presented for this table. Both options revise the table to include more detailed descriptions of heating systems and supplemental systems. Option 1 is the initial technical advisory group recommendation based on the original proposal and the goal of achieving the required energy savings for the cycle. Option 2 is a revised proposal that takes into account the other code change proposals going forward to public hearing and the changes in equipment values based on the new requirements in the proposed rule.	The cost models were based on the changes moving forwards as Option 1. If Option 2 is the option moving forward, the cost will decrease from that of the 2018 code for most dwellings based on the reduced number of additional efficiency credits required. Costs will vary depending on the options selected. There was no comparison of the difference in cost between the 2018 and 2021 requirements, but only a measure by measure estimate of cost based on 6 prototype buildings. Those costs ranged from $173 to $5,245 per dwelling. Energy savings for various prototype buildings and systems range from 4 kWh to 1941 kWh annually.
	R406.3 Additional energy efficiency requirements. Again, there are two options being presented for this table. Both tables include a new 150 square foot threshold for additions to trigger this requirement. Option 1 is the initial technical advisory group recommendation based on the original proposal and the goal of achieving the required energy savings for the cycle. Option 2 is a revised proposal that takes into account the other code change proposals going forward to public hearing and the reduction in energy use based on the new requirements in the proposed rule.
	Table R406.3 Energy credits. This section also has two options. For both options, one half point is equivalent to a 600 kWh energy savings. Some options were eliminated due to the fact they are now a part of the base code requirements. Option 1 is the initial technical advisory group recommendation based on the original proposal. The credits are based on the heating system type from Table R406.2. Option 2 is a revised proposal that takes into account the other code change proposals going forward to public hearing. Based on the heat pump space and water heating changes, there is no differentiating between the systems types for point values. Instead, there are options that are just not available with some systems types, as identified by footnote d. Some options are no longer available based on the fact that the base requirements now incorporate the provisions contained therein; some are just adjusted to yield a similar energy savings over the base code, or the point value is changed based on the savings reflected.
21-GP2-080	R403.5.5 Water heater installation location. This section requires that water heaters be located within conditioned space except for highly efficient water heaters where the standby losses are overcome by the efficiency of the unit performance.	Cost: Estimated cost of about $746 per dwelling unit or $0.33 per square foot. Energy Savings: Estimated annual energy savings of 271 kWh per dwelling unit.
21-GP2-032	R403.3.4.1 Sealed air handler. This change requires the air handler to be located within the conditioned space.	Cost: Estimated incremental cost of $100 per dwelling unit. Energy Savings: Estimated annual energy savings is $30 to $60.

21-GP2-089	R402.4.1.3 Leakage rate. The maximum leakage rate was reduced to 3 air changes per hour for single family and 0.25 cfm (the same as the commercial requirement) for multifamily.	It was deemed there is no increase in cost. While the leakage rate was reduced, the cost of testing remains the same. More attention must be paid to construction best practices to adequately seal the building thermal envelope.
21-GP2-035	R502.3.1.1 Existing ceilings with attic spaces. This new section requires that when additions over 150 square feet adjoin existing attic spaces, the existing attic space needs to be brought into full compliance with the envelope provisions in R402.	This proposal was tied to the new exception exempting additions less than 150 square feet from Section C406 compliance and was not evaluated separately for costs and energy savings. There would be an added cost based on the square footage of existing attic space needing to be upgraded. Estimated cost is between $0.80 and $2.60 per square foot. Estimated annual energy savings is approximately 0.6 percent.
21-GP2-088	R402.4.1.2 Testing. The specifics on the testing standard were moved from the exception into the main body of the section and the test must include information on the time, date and location where performed. Requirements were also added that the testing personnel be trained by an accredited program. The second exception from the second set of exceptions was moved to Section R402.4.1.3. The volume adjustment capping the ceiling height at 8.5 feet was removed.	There was some debate at the TAG as to whether there would be a cost associated with this measure, focusing on the requirement for training from an accredited program. Ultimately, it was determined that there would be little to no increase. There are no energy savings associated with this proposal, other than ensuring proper testing to achieve the originally intended savings.
The following proposals add options to the menu of additional energy efficiency credits to be selected. These are optional items that may be selected as part of the package for the required credits.
21-GP2-023	Table R406.3 Energy credits. Option 3.2 requires a cold climate heat pump to be used in areas with a winter design temperature at 23° or below.	Cost: Estimated incremental cost is $1000 per dwelling unit. Energy savings: Estimated annual energy savings of 4,000 kWh, or $400 per year.
21-GP2-024	Table R406.3 Energy credits. Option 3.5 allows an alternate cold climate 10 HSPF heat pump to be substituted for an 11 HSPF heat pump but will require a cold climate heat pump similar to Option 3.2 in 023, above.	Cost: Estimated incremental cost is $1500 per dwelling unit. Energy savings: Estimated annual energy savings of 4,000 kWh, or $400 per year.
21-GP2-025	Table R406.3 Energy credits. Option 3.6 also allows a substitution of a 9 HSPF heat pump for the required 10 HSPF in some cases.	Cost: Estimated incremental cost is $1500 per dwelling unit. Energy savings: Negligible for single zone systems, but significant for multi-zone systems.
21-GP2-050	Table R406.3 Energy credits. New Option 3.7 provides credit for an air to water heat pump with a COP rating of 3.2.	Cost: Estimated incremental cost is $4000 per dwelling unit. Energy savings: Estimated annual energy savings of 6,000 to 12,000 kWh, or $700 to $1400 per year.
21-GP2-034	Table R406.3 Energy credits. New Option 3.8 allows a half credit for a connected thermostat.	Cost: Estimated incremental cost is $200 per dwelling unit. Energy savings: Estimated annual energy savings of 600 kWh, or $60 per year.

Loss of Sales or Revenue: The proposed rules make the state code for building construction consistent with national standards. Businesses with new products or updated testing or design standards are recognized in the updated building code. For these businesses there will be a gain in sales and revenue.

The results of reduced energy use in buildings include avoiding the need for new power generation, reducing environmental impact, and providing local employment. The legislative findings state that energy efficiency is the cheapest, quickest, and cleanest way to meet rising energy needs, confront climate change, and boost our economy.

Cost of Compliance for Small Businesses: The majority of businesses affected by the updates to the building codes are small businesses, over 95 percent of those listed in the construction and related industries have under 50 employees. The costs per employee are comparable between the largest businesses and the majority of small businesses. The cost to comply with the updated codes is not a disproportionate impact on small businesses. Where the council found the cost of compliance for small businesses to be disproportionate, the proposed rule sought to mitigate the cost through modification of the proposal. The proposed rules include a definition of small business and provide exceptions for compliance with the updated rule.

Small Businesses Involved in the Development of the Rule: SBCC conducted open public meetings of the energy code TAG, available via Zoom and telephone conference bridge, and allowed comment on every item on every agenda. SBCC appointed over 100 representatives of all segments of the business and construction community to serve on the various TAGs.

List of Industries: Below is a list of industries required to comply with the commercial energy code:

2017 Industry NAICS Code	NAICS Code Title	Minor Cost Estimate	1% of Avg Annual Payroll	0.3% of Avg Annual Gross Business Income
236116	New Multifamily Housing Construction (except For-Sale Builders)	$32,067.43	$17,160.94* 2020 Dataset pulled from USBLS	$32,067.43 2020 Dataset pulled from DOR
236118	Residential Remodelers	$1,457.74	$1,457.74* 2020 Dataset pulled from USBLS	$901.20 2020 Dataset pulled from DOR
238110	Poured Concrete Foundation and Structure Contractors	$3,442.28	$5,027.07 2019 Dataset pulled from CBP	$3,442.28 2020 Dataset pulled from DOR
238120	Structural Steel and Precast Concrete Contractors	$15,401.97	$20,212.19 2019 Dataset pulled from CBP	$15,401.97 2020 Dataset pulled from DOR
238130	Framing Contractors	$2,234.30	$3,139.71 2019 Dataset pulled from CBP	$2,234.30 2020 Dataset pulled from DOR
238140	Masonry Contractors	$1,900.60	$3,582.13 2019 Dataset pulled from CBP	$1,900.60 2020 Dataset pulled from DOR
238150	Glass and Glazing Contractors	$5,255.36	$9,574.95 2019 Dataset pulled from CBP	$5,255.36 2020 Dataset pulled from DOR
238160	Roofing Contractors	$3,589.99	$5,007.86 2019 Dataset pulled from CBP	$3,589.99 2020 Dataset pulled from DOR
238170	Siding Contractors	$1,905.61	$2,485.86 2019 Dataset pulled from CBP	$1,905.61 2020 Dataset pulled from DOR
238190	Other Foundation; Structure; and Building Exterior Contractors	$4,622.07	$4,141.38 2019 Dataset pulled from CBP	$4,622.07 2020 Dataset pulled from DOR
238210	Electrical Contractors and Other Wiring Installation Contractors	$5,941.60	$9,599.33 2019 Dataset pulled from CBP	$5,941.60 2020 Dataset pulled from DOR
238220	Plumbing; Heating; and Air-Conditioning Contractors	$5,353.76	$11,047.00 2019 Dataset pulled from CBP	$5,353.76 2020 Dataset pulled from DOR
238290	Other Building Equipment Contractors	$4,335.21	$16,142.07 2019 Dataset pulled from CBP	$4,335.21 2020 Dataset pulled from DOR
238310	Drywall and Insulation Contractors	$3,725.66	$9,461.67 2019 Dataset pulled from CBP	$3,725.66 2020 Dataset pulled from DOR
238990	All Other Specialty Trade Contractors	$3,585.74	$3,677.28 2019 Dataset pulled from CBP	$3,585.74 2020 Dataset pulled from DOR
321214	Truss Manufacturing	$28,620.35	$23,341.04 2020 Dataset pulled from ESD	$28,620.35 2020 Dataset pulled from DOR
321911	Wood Window and Door Manufacturing	$45,151.12	$18,811.08 2020 Dataset pulled from ESD	$45,151.12 2020 Dataset pulled from DOR
327310	Cement Manufacturing	$50,878.29	$44,741.20 2020 Dataset pulled from ESD	$50,878.29 2020 Dataset pulled from DOR
327320	Ready-Mix Concrete Manufacturing	$64,317.30	$46,126.21 2020 Dataset pulled from ESD	$64,317.30 2020 Dataset pulled from DOR
327331	Concrete Block and Brick Manufacturing	$15,030.60	$15,030.60 2020 Dataset pulled from ESD	$10,431.02 2020 Dataset pulled from DOR
332312	Fabricated Structural Metal Manufacturing	$22,220.31	$16,337.10 2020 Dataset pulled from USBLS	$22,220.31 2020 Dataset pulled from DOR
332321	Metal Window and Door Manufacturing	$26,369.28	$14,505.40 2020 Dataset pulled from ESD	$26,369.28 2020 Dataset pulled from DOR
332322	Sheet Metal Work Manufacturing	$23,337.23	$23,337.23 2020 Dataset pulled from ESD	$16,556.52 2020 Dataset pulled from DOR
335121	Residential Electric Lighting Fixture Manufacturing	$2,011.37	$2,011.37 2020 Dataset pulled from USBLS	$1,502.01 2020 Dataset pulled from DOR
335129	Other Lighting Equipment Manufacturing	$6,281.32	$6,281.32 2020 Dataset pulled from ESD	$2,494.40 2020 Dataset pulled from DOR
423720	Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers	$24,486.53	$16,589.10 2020 Dataset pulled from ESD	$24,486.53 2020 Dataset pulled from DOR
541310	Architectural Services	$9,221.65	$9,221.65 2020 Dataset pulled from ESD	$3,738.99 2020 Dataset pulled from DOR
541330	Engineering Services	$14,801.92	$14,801.92 2020 Dataset pulled from USBLS	$7,177.43 2020 Dataset pulled from DOR

A copy of the statement may be obtained by contacting Stoyan Bumbalov, P.O. Box 41449, Olympia, WA 98504-1449, phone 360-407-9255, email sbcc@des.wa.gov.

August 23, 2022

Tony Doan

Council Chair

OTS-4009.2

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-10100Section R101—Scope and general requirements.

R101.1 Title. This code shall be known as the Washington State Energy Code-Residential, and shall be cited as such. It is referred to herein as "this code."

The 2021 edition of the Washington State Energy Code is hereby adopted. The Washington State Energy Code adopted under chapter 51-11R WAC shall become effective in all counties and cities of this state on July 1, 2023.

R101.2 Scope. This code applies to residential buildings and the buildings sites and associated systems and equipment. This code shall be the maximum and minimum energy code for residential construction in each town, city and county. Residential sleeping units, Group I-1, Condition 2 assisted living facilities licensed by Washington state under chapter 388-78A WAC and Group I-1, Condition 2 residential treatment facilities licensed by Washington state under chapter 246-337 WAC shall utilize the commercial building sections of the energy code regardless of the number of stories of height above grade plane.

R101.3 Intent. This code shall regulate the design and construction of buildings for the effective use and conservation of energy over the useful life of each building. This code is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this objective. This code is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances.

R101.4 Applicability. Where, in any specific case, different sections of this code specify different materials, methods of construction or other requirements, the most restrictive shall govern. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall govern.

R101.4.1 Mixed residential and commercial buildings. Where a building includes both residential building and commercial building portions, each portion shall be separately considered and meet the applicable provisions of the WSEC - Commercial or WSEC - Residential Provisions.

R101.5 Compliance.Residential buildings shall meet the provisions of WSEC - Residential Provisions. Commercial buildings shall meet the provisions of WSEC - Commercial Provisions.

R101.5.1 Compliance materials. The code official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this code.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-10200Section R102—Alternative materials, design and methods of construction and equipment.

R102.1 General. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. The code official shall have the authority to approve an alternative material, design or method of construction upon the written application of the owner or owner's authorized agent. The code official shall first find that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, not less than the equivalent of that prescribed in this code for strength, effectiveness, fire resistance, durability, energy efficiency and safety. ((Where the alternative material, design or method of construction is not approved,))The code official shall respond in writing, stating the reason why the alternative was approved or was not approved.

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-10300Section R103—Construction documents.

R103.1 General. Construction documents, technical report, and other supporting data shall be submitted in one or more sets, or in a digital format where allowed by the code official, with each application for a permit. The construction documents and technical reports shall be prepared by a registered design professional where required by the statutes of the jurisdiction in which the project is to be constructed. Where special conditions exist, the code official is authorized to require necessary construction documents to be prepared by a registered design professional.

EXCEPTION:

The code official is authorized to waive the requirements for construction documents or other supporting data if the code official determines they are not necessary to confirm compliance with this code.

R103.2 Information on construction documents. Construction documents shall be drawn to scale upon suitable material. Electronic media documents are permitted to be submitted when approved by the code official. Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as herein governed. Details shall include, but are not limited to, the following as applicable:

1. Energy compliance path per Section R401.2.

2. Insulation materials and their R-values.

((2.))3. Fenestration U-factors and SHGCs.

((3.))4. Area-weighted U-factor and SHGC calculations.

((4.))5. Mechanical system design criteria.

((5.))6. Mechanical and service water heating system and equipment types, sizes and efficiencies.

((6.))7. Equipment and systems controls.

((7.))8. Duct sealing, duct and pipe insulation and location.

((8.))9. Air sealing details.

R103.2.1 Building thermal envelope depiction. The building's thermal envelope shall be represented on the construction documents.

R103.3 Examination of documents. The code official shall examine or cause to be examined the accompanying construction documents and shall ascertain whether the construction indicated and described is in accordance with the requirements of this code and other pertinent laws or ordinances. The code official is authorized to utilize a registered design professional or other approved entity not affiliated with the building design or construction in conducting the review of the plans and specifications for compliance with the code.

R103.3.1 Approval of construction documents. When the code official issues a permit where construction documents are required, the construction documents shall be endorsed in writing and stamped "Reviewed for Code Compliance." Such approved construction documents shall not be changed, modified or altered without authorization from the code official. Work shall be done in accordance with the approved construction documents.

One set of construction documents so reviewed shall be retained by the code official. The other set shall be returned to the applicant, kept at the site of work and shall be open to inspection by the code official or a duly authorized representative.

R103.3.2 Previous approvals. This code shall not require changes in the construction documents, construction or designated occupancy of a structure for which a lawful permit has been heretofore issued or otherwise lawfully authorized, and the construction of which has been pursued in good faith within 180 days after the effective date of this code and has not been abandoned.

R103.3.3 Phased approval. The code official shall have the authority to issue a permit for the construction of part of an energy conservation system before the construction documents for the entire system have been submitted or approved, provided adequate information and detailed statements have been filed complying with all pertinent requirements of this code. The holders of such permit shall proceed at their own risk without assurance that the permit for the entire energy conservation system will be granted.

R103.4 Amended construction documents. Work shall be installed in accordance with the approved construction documents, and any changes made during construction that are not in compliance with the approved construction documents shall be resubmitted for approval as an amended set of construction documents.

R103.5 Retention of construction documents. One set of approved construction documents shall be retained by the code official for a period of not less than 180 days from date of completion of the permitted work, or as required by state or local laws.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-10400Section R104—((Inspections))Fees.

((R104.1 General. Construction or work for which a permit is required shall be subject to inspection by the code official or his or her designated agent, and such construction or work shall remain visible and able to be accessed for inspection purposes until approved. It shall be the duty of the permit applicant to cause the work to remain visible and able to be accessed for inspection purposes. Neither the code official nor the jurisdiction shall be liable for expense entailed in the removal or replacement of any material, product, system or building component required to allow inspection to validate compliance with this code.

R104.2 Required inspections. The code official or his or her designated agent, upon notification, shall make the inspections set forth in Sections R104.2.1 through R104.2.5.

R104.2.1 Footing and foundation inspection. Inspections associated with footings and foundations shall verify compliance with the code as to R-value, location, thickness, depth of burial and protection of insulation as required by the code and approved plans and specifications.

R104.2.2 Framing and rough-in inspection. Inspections at framing and rough-in shall be made before application of interior finish and shall verify compliance with the code as to types of insulation and corresponding R-values and their correct location and proper installation; fenestration properties (U-factor and SHGC) and proper installation; and air leakage controls as required by the code and approved plans and specifications.

R104.2.2.1 Wall insulation inspection. The code official, upon notification, shall make a wall insulation inspection in addition to those inspections required in Section R109 of the International Residential Code. This inspection shall be made after all wall and cavity insulation is in place and prior to cover.

R104.2.3 Plumbing rough-in inspection. Inspections at plumbing rough-in shall verify compliance as required by the code and approved plans and specifications as to types of insulation and corresponding R-values and protection, and required controls.

R104.2.4 Mechanical rough-in inspection. Inspections at mechanical rough-in shall verify compliance as required by the code and approved plans and specifications as to installed HVAC equipment type and size, required controls, system insulation and corresponding R-value, system air leakage control, programmable thermostats, dampers, whole-house ventilation and minimum fan efficiency.

EXCEPTION:

Systems serving multiple dwelling units shall be inspected in accordance with Section C104.2.4.

R104.2.5 Final inspection. The building shall have a final inspection and not be occupied until approved.

R104.3 Reinspection. A building shall be reinspected when determined necessary by the code official.

R104.4 Approved inspection agencies. The code official is authorized to accept reports of third-party inspection agencies not affiliated with the building design or construction, provided such agencies are approved as to qualifications and reliability relevant to the building components and systems they are inspecting.

R104.5 Inspection requests. It shall be the duty of the holder of the permit or their duly authorized agent to notify the code official when work is ready for inspection. It shall be the duty of the permit holder to provide access to and means for inspections of such work that are required by this code.

R104.6 Reinspection and testing. Where any work or installation does not pass an initial test or inspection, the necessary corrections shall be made so as to achieve compliance with this code. The work or installation shall then be resubmitted to the code official for inspection and testing.

R104.7 Approval. After the prescribed tests and inspections indicate that the work complies in all respects with this code, a notice of approval shall be issued by the code official.

R104.7.1 Revocation. The code official is authorized to, in writing, suspend or revoke a notice of approval issued under the provisions of this code wherever the certificate is issued in error, or on the basis of incorrect information supplied, or where it is determined that the building or structure, premise, or portion thereof is in violation of any ordinance or regulation or any of the provisions of this code.))

R104.1 Fees. A permit shall not be issued until the fees prescribed in Section R107.2 have been paid, nor shall an amendment to a permit be released until the additional fee, if any, has been paid.

R104.2 Schedule of permit fees. A fee for each permit shall be paid as required, in accordance with the schedule as established by the applicable governing authority.

R104.3 Work commencing before permit issuance. Any person who commences any work before obtaining the necessary permits shall be subject to an additional fee established by the code official, which shall be in addition to the required permit fees.

R104.4 Related fees. The payment of the fee for the construction, alteration, removal, or demolition of work done in connection to or concurrently with the work or activity authorized by a permit shall not relieve the applicant or holder of the permit from the payment of other fees that are prescribed by law.

R104.5 Refunds. The code official is authorized to establish a refund policy.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-10500Section R105—((Validity))Inspections.

R105.1 General.((If a portion of this code is held to be illegal or void, such a decision shall not affect the validity of the remainder of this code.))Construction or work for which a permit is required shall be subject to inspection by the code official or his or her designated agent, and such construction or work shall remain visible and able to be accessed for inspection purposes until approved. It shall be the duty of the permit applicant to cause the work to remain visible and able to be accessed for inspection purposes. Neither the code official nor the jurisdiction shall be liable for expense entailed in the removal or replacement of any material, product, system or building component required to allow inspection to validate compliance with this code.

R105.2 Required inspections. The code official or his or her designated agent, upon notification, shall make the inspections set forth in Sections R104.2.1 through R104.2.5.

R105.2.1 Footing and foundation inspection. Inspections associated with footings and foundations shall verify compliance with the code as to R-value, location, thickness, depth of burial and protection of insulation as required by the code and approved plans and specifications.

R105.2.2 Framing and rough-in inspection. Inspections at framing and rough-in shall be made before application of interior finish and shall verify compliance with the code as to types of insulation and corresponding R-values and their correct location and proper installation; fenestration properties (U-factor and SHGC) and proper installation; and air leakage controls as required by the code and approved plans and specifications.

R105.2.2.1 Wall insulation inspection. The code official, upon notification, shall make a wall insulation inspection in addition to those inspections required in Section R109 of the International Residential Code. This inspection shall be made after all wall and cavity insulation is in place and prior to cover.

R105.2.3 Plumbing rough-in inspection. Inspections at plumbing rough-in shall verify compliance as required by the code and approved plans and specifications as to types of insulation and corresponding R-values and protection, and required controls.

R105.2.4 Mechanical rough-in inspection. Inspections at mechanical rough-in shall verify compliance as required by the code and approved plans and specifications as to installed HVAC equipment type and size, required controls, system insulation and corresponding R-value, system air leakage control, programmable thermostats, dampers, whole-house ventilation and minimum fan efficiency.

EXCEPTION:

Systems serving multiple dwelling units shall be inspected in accordance with Section C104.2.4.

R105.2.5 Final inspection. The building shall have a final inspection and not be occupied until approved.

R105.3 Reinspection. A building shall be reinspected when determined necessary by the code official.

R105.4 Approved inspection agencies. The code official is authorized to accept reports of third-party inspection agencies not affiliated with the building design or construction, provided such agencies are approved as to qualifications and reliability relevant to the building components and systems they are inspecting.

R105.5 Inspection requests. It shall be the duty of the holder of the permit or their duly authorized agent to notify the code official when work is ready for inspection. It shall be the duty of the permit holder to provide access to and means for inspections of such work that are required by this code.

R105.6 Reinspection and testing. Where any work or installation does not pass an initial test or inspection, the necessary corrections shall be made so as to achieve compliance with this code. The work or installation shall then be resubmitted to the code official for inspection and testing.

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-10600Section R106—((Referenced standards))Notice of approval.

((R106.1 Referenced codes and standards. The codes and standards referenced in this code shall be those listed in Chapter 5, and such codes and standards shall be considered as part of the requirements of this code to the prescribed extent of each such reference and as further regulated in Sections R106.1.1 and R106.1.2.

R106.1.1 Conflicts. Where differences occur between provisions of this code and referenced codes and standards, the provisions of this code shall apply.

R106.1.2 Provisions in referenced codes and standards. Where the extent of the reference to a referenced code or standard includes subject matter that is within the scope of this code, the provisions of this code, as applicable, shall take precedence over the provisions in the referenced code or standard.

R106.2 Application of references. References to chapter or section numbers, or to provisions not specifically identified by number, shall be construed to refer to such chapter, section or provision of this code.

R106.3 Other laws. The provisions of this code shall not be deemed to nullify any provisions of local, state or federal law. In addition to the requirements of this code, all occupancies shall conform to the provisions included in the state building code (chapter 19.27 RCW). In case of conflicts among codes enumerated in RCW 19.27.031 (1) through (4) and this code, an earlier named code shall govern over those following. In the case of conflict between the duct sealing and insulation requirements of this code and the duct insulation requirements of Sections 603 and 604 of the International Mechanical Code, the duct insulation requirements of this code shall govern.))

R106.1 Approval. After the prescribed tests and inspections indicate that the work complies in all respects with this code, a notice of approval shall be issued by the code official.

R106.2 Revocation. The code official is authorized to, in writing, suspend or revoke a notice of approval issued under the provisions of this code wherever the certificate is issued in error, or on the basis of incorrect information supplied, or where it is determined that the building or structure, premise, or portion thereof is in violation of any ordinance or regulation or any of the provisions of this code.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-10700Section R107—((Fees))Validity.

((R107.1 Fees. A permit shall not be issued until the fees prescribed in Section R107.2 have been paid, nor shall an amendment to a permit be released until the additional fee, if any, has been paid.

R107.2 Schedule of permit fees. A fee for each permit shall be paid as required, in accordance with the schedule as established by the applicable governing authority.

R107.3 Work commencing before permit issuance. Any person who commences any work before obtaining the necessary permits shall be subject to an additional fee established by the code official, which shall be in addition to the required permit fees.

R107.4 Related fees. The payment of the fee for the construction, alteration, removal or demolition of work done in connection to or concurrently with the work or activity authorized by a permit shall not relieve the applicant or holder of the permit from the payment of other fees that are prescribed by law.

R107.5 Refunds. The code official is authorized to establish a refund policy.))

R107.1 General. If a portion of this code is held to be illegal or void, such a decision shall not affect the validity of the remainder of this code.

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-10800Section R108—((Stop work order))Referenced standards.

((R108.1 Authority. Whenever the code official finds any work regulated by this code being performed in a manner either contrary to the provisions of this code or dangerous or unsafe, the code official is authorized to issue a stop work order.

R108.2 Issuance. The stop work order shall be in writing and shall be given to the owner of the property involved, or to the owner's authorized agent, or to the person doing the work. Upon issuance of a stop work order, the cited work shall immediately cease. The stop work order shall state the reason for the order, and the conditions under which the cited work will be permitted to resume.

R108.3 Emergencies. Where an emergency exists, the code official shall not be required to give a written notice prior to stopping the work.

R108.4 Failure to comply. Any person who shall continue any work after having been served with a stop work order, except such work as that person is directed to perform to remove a violation or unsafe condition, shall be subject to a fine as set by the applicable governing authority.))

R108.1 Referenced codes and standards. The codes and standards referenced in this code shall be those listed in Chapter 5, and such codes and standards shall be considered as part of the requirements of this code to the prescribed extent of each such reference and as further regulated in Sections R106.1.1 and R106.1.2.

R108.1.1 Conflicts. Where differences occur between provisions of this code and referenced codes and standards, the provisions of this code shall apply.

R108.1.2 Provisions in referenced codes and standards. Where the extent of the reference to a referenced code or standard includes subject matter that is within the scope of this code, the provisions of this code, as applicable, shall take precedence over the provisions in the referenced code or standard.

R108.2 Application of references. References to chapter or section numbers, or to provisions not specifically identified by number, shall be construed to refer to such chapter, section, or provision of this code.

R108.3 Other laws. The provisions of this code shall not be deemed to nullify any provisions of local, state, or federal law. In addition to the requirements of this code, all occupancies shall conform to the provisions included in the state building code (chapter 19.27 RCW). In case of conflicts among codes enumerated in RCW 19.27.031 (1) through (4) and this code, an earlier named code shall govern over those following. In the case of conflict between the duct sealing and insulation requirements of this code and the duct insulation requirements of Sections 603 and 604 of the International Mechanical Code, the duct insulation requirements of this code shall govern.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-10900Section R109—((Board of appeals))Stop work order.

((R109.1 General. In order to hear and decide appeals of orders, decisions or determinations made by the code official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The code official shall be an ex officio member of said board but shall have no vote on any matter before the board. The board of appeals shall be appointed by the governing body and shall hold office at its pleasure. The board shall adopt rules of procedure for conducting its business, and shall render all decisions and findings in writing to the appellant with a duplicate copy to the code official.

R109.2 Limitations on authority. An application for appeal shall be based on a claim that the true intent of this code or the rules legally adopted thereunder have been incorrectly interpreted, the provisions of this code do not fully apply or an equally good or better form of construction is proposed. The board shall have no authority to waive requirements of this code.

R109.3 Qualifications. The board of appeals shall consist of members who are qualified by experience and training and are not employees of the jurisdiction.))

R109.1 Authority. Whenever the code official finds any work regulated by this code being performed in a manner either contrary to the provisions of this code or dangerous or unsafe, the code official is authorized to issue a stop work order.

R109.2 Issuance. The stop work order shall be in writing and shall be given to the owner of the property involved, or to the owner's authorized agent, or to the person doing the work. Upon issuance of a stop work order, the cited work shall immediately cease. The stop work order shall state the reason for the order, and the conditions under which the cited work will be permitted to resume.

R109.3 Emergencies. Where an emergency exists, the code official shall not be required to give a written notice prior to stopping the work.

R109.4 Failure to comply. Any person who shall continue any work after having been served with a stop work order, except such work as that person is directed to perform to remove a violation or unsafe condition, shall be subject to a fine as set by the applicable governing authority.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-11000Section R110—((Violations))Means of appeal.

((It shall be unlawful for any person, firm, or corporation to erect or construct any building, or remodel or rehabilitate any existing building or structure in the state, or allow the same to be done, contrary to or in violation of any of the provisions of this code.))

R110.1 General. In order to hear and decide appeals of orders, decisions or determinations made by the code official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The code official shall be an ex officio member of said board but shall have no vote on any matter before the board. The board of appeals shall be appointed by the governing body and shall hold office at its pleasure. The board shall adopt rules of procedure for conducting its business, and shall render all decisions and findings in writing to the appellant with a duplicate copy to the code official.

R110.2 Limitations on authority. An application for appeal shall be based on a claim that the true intent of this code or the rules legally adopted thereunder have been incorrectly interpreted, the provisions of this code do not fully apply or an equally good or better form of construction is proposed. The board shall have no authority to waive requirements of this code.

R110.3 Qualifications. The board of appeals shall consist of members who are qualified by experience and training and are not employees of the jurisdiction.

R110.4 Administration. The code official shall take immediate action in accordance with the decision of the board.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-11100Section R111—((Liability))Violations.

((Nothing contained in this code is intended to be nor shall be construed to create or form the basis for any liability on the part of any city or county or its officers, employees or agents for any injury or damage resulting from the failure of a building to conform to))It shall be unlawful for any person, firm, or corporation to erect or construct any building, or remodel or rehabilitate any existing building or structure in the state, or allow the same to be done, contrary to or in violation of any of the provisions of this code.

NEW SECTION

WAC 51-11R-11200Section R112—Liability.

Nothing contained in this code is intended to be nor shall be construed to create or form the basis for any liability on the part of any city or county or its officers, employees, or agents for any injury or damage resulting from the failure of a building to conform to the provisions of this code.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-20201Section R202.1—A.

ABOVE-GRADE WALL. A wall enclosing conditioned space that is not a below-grade wall. This includes between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable end walls, walls enclosing a mansard roof and skylight shafts.

((ACCESSIBLE. Admitting close approach as a result of not being guarded by locked doors, elevation or other effective means (see "Readily accessible").))ACCESS (TO). That which enables a device, appliance, or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel or similar obstruction.

ADDITION. An extension or increase in the conditioned space floor area, number of stories or height of a building or structure.

ADVANCED FRAMED WALLS. Studs framed on 24-inch centers with double top plate and single bottom plate. Corners use two studs or other means of fully insulating corners, and one stud is used to support each header. Headers consist of double 2x material with R-10 insulation between the header and exterior sheathing. Interior partition wall/exterior wall intersections are fully insulated in the exterior wall. (See Standard Framing and Appendix A, of this code.)

AIR BARRIER. One or more materials joined together in a continuous manner to restrict or prevent the passage of air through the building thermal envelope and its assemblies.

((AIR-IMPERMEABLE INSULATION. An insulation that functions as an air barrier material.))

ALTERATION. Any construction, retrofit or renovation to an existing structure other than repair or addition. Also, a change in a building, electrical, gas, mechanical or plumbing system that involves an extension, addition or change to the arrangement, type or purpose of the original installation.

APPROVED. Acceptable to the code official.

APPROVED AGENCY. An established and recognized agency that is regularly engaged in conducting tests or furnishing inspection services, or furnishing product certification, where such agency has been approved by the code official.

AUTOMATIC. Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for example, a change in current strength, pressure, temperature or mechanical configuration (see "Manual").

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-20203Section R202.3—C.

C-FACTOR (THERMAL CONDUCTANCE). The coefficient of heat transmission (surface to surface) through a building component or assembly, equal to the time rate of heat flow per unit area and the unit temperature difference between the warm side and cold side surfaces (Btu/h ft2 × °F) [W/(m2 × K)].

CAVITY INSULATION. Insulating material located between framing members.

CIRCULATING HOT WATER SYSTEM. A specifically designed water distribution system where one or more pumps are operated in the service hot water piping to circulate heated water from the water-heating equipment to the fixture supply and back to the water-heating equipment.

CLIMATE ZONE. A geographical region based on climatic criteria as specified in this code.

CODE OFFICIAL. The officer or other designated authority charged with the administration and enforcement of this code, or a duly authorized representative.

COMMERCIAL BUILDING. For this code, all buildings that are not included in the definition of "Residential buildings."

CONDITIONED FLOOR AREA. The horizontal projection of the floors associated with the conditioned space.

CONDITIONED SPACE. An area, room or space that is enclosed within the building thermal envelope and that is directly or indirectly heated or cooled. Spaces are indirectly heated or cooled where they communicate through openings with conditioned spaces, where they are separated from conditioned spaces by uninsulated walls, floors or ceilings, or where they contain uninsulated ducts, piping or other sources of heating or cooling.

CONNECTED THERMOSTAT. An internet enabled device that automatically adjusts heating and cooling temperature settings.

CONTINUOUS AIR BARRIER. A combination of materials and assemblies that restrict or prevent the passage of air through the building thermal envelope.

CONTINUOUS INSULATION (c.i.). Insulating material that is continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope.

CURTAIN WALL. Fenestration products used to create an external nonload-bearing wall that is designed to separate the exterior and interior environments.

Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency and appear in the Register pursuant to the requirements of RCW 34.08.040.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-20204Section R202.4—D.

DEMAND RECIRCULATION WATER SYSTEM. A water distribution system ((having))where one or more ((recirculation pumps that pump water from a heated water supply pipe back to the heated water source through a cold water supply pipe))pumps prime the service hot water piping with heated water upon demand for hot water.

DIMMER. A control device that is capable of continuously varying the light output and energy use of light sources.

DUCT. A tube or conduit utilized for conveying air. The air passages of self-contained systems are not to be construed as air ducts.

DUCT SYSTEM. A continuous passageway for the transmission of air that, in addition to ducts, includes duct fittings, dampers, plenums, fans and accessory air-handling equipment and appliances.

DUCTLESS MINI-SPLIT HEAT PUMP SYSTEM. A heating and cooling system that is comprised of one or multiple indoor evaporator/air-handling units and an outdoor condensing unit that is connected by refrigerant piping and electrical wiring. A ductless mini-split system is capable of cooling or heating one or more rooms without the use of a central ductwork system.

DWELLING UNIT. A single unit providing complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation.

DWELLING UNIT ENCLOSURE AREA. The sum of the area of ceiling, floors, and walls separating a dwelling unit's conditioned space from the exterior or from adjacent conditioned or unconditioned spaces. Wall height shall be measured from the finished floor of the dwelling unit to the underside of the floor above.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-20206Section R202.6—F.

FENESTRATION. Products classified as either vertical fenestration or skylights.

VERTICAL FENESTRATION. Windows (fixed or operable), glazed doors, glazed block and combination opaque/glazed doors composed of glass or other transparent or translucent glazing materials and installed at a slope of not less than 60 degrees from horizontal. Opaque areas such as spandrel panels are not considered vertical fenestration.

SKYLIGHT. Glass or other transparent or translucent glazing material installed with a slope of less than 60 degrees from horizontal, including unit skylights, tubular daylighting devices and glazing materials in solariums, sunrooms, roofs, and sloped walls.

FENESTRATION AREA. Total area of the fenestration measured using the rough opening, and including the glazing, sash and frame.

FENESTRATION PRODUCT, FIELD-FABRICATED. A fenestration product whose frame is made at the construction site of standard dimensional lumber or other materials that were not previously cut, or otherwise formed with the specific intention of being used to fabricate a fenestration product or exterior door. Field fabricated does not include site-built fenestration.

FENESTRATION PRODUCT, SITE-BUILT. A fenestration designed to be made up of field-glazed or field-assembled units using specific factory cut or otherwise factory-formed framing and glazing units. Examples of site-built fenestration include storefront systems, curtain walls, and atrium roof systems.

F-FACTOR. The perimeter heat loss factor for slab-on-grade floors (Btu/h × ft × °F) [W/(m × K)].

Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency and appear in the Register pursuant to the requirements of RCW 34.08.040.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-20208Section R202.8—H.

HEATED SLAB-ON-GRADE FLOOR. Slab-on-grade floor construction in which the heating elements, hydronic tubing, or hot air distribution system is in contact with, or placed within or under, the slab.

HIGH-EFFICACYLIGHT SOURCES.((Fixtures that use light emitting diodes (LED), T-8 or smaller diameter linear fluorescent lamps, or other lamps with a minimum efficacy of 65 lumens per watt.))Compact fluorescent lamps, light emitting diode (LED) lamps, T-8 or smaller diameter linear fluorescent lamps, or other lamps with an efficacy of not less than 65 lumens per watt, or luminaires with an efficacy of not less than 45 lumens per watt.

HISTORIC BUILDINGS. Buildings that are listed in or eligible for listing in the National Register of Historic Places, or designated as historic under an appropriate state or local law.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-20215Section R202.15—O.

OCCUPANT SENSOR CONTROL. An automatic control device that detects the presence or absence of people within an area and causes lighting, equipment, or appliances to be regulated accordingly.

ON-SITE RENEWABLE ENERGY. Energy from renewable energy resources harvested at the building site.

OPAQUE DOOR. A door that is not less than 50 percent opaque in surface area.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-20218Section R202.18—R.

((READILY ACCESSIBLE. Capable of being reached quickly for operation, renewal or inspection without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders or access equipment (see "Accessible").))READY ACCESS (TO). That which enables a device, appliance, or equipment to be directly reached without requiring the removal or movement of any panel or similar obstruction.

RENEWABLE ENERGY CERTIFICATE (REC). An instrument that represents the environmental attributes of one megawatt hour of renewable energy; also known as an energy attribute certificate (EAC).

RENEWABLE ENERGY RESOURCES. Energy derived from solar radiation, wind, waves, tides, landfill gas, biogas, biomass, or extracted from hot fluid or steam heated within the earth.

REPAIR. The reconstruction or renewal of any part of an existing building for the purpose of its maintenance or to correct damage.

REROOFING. The process of recovering or replacing an existing roof covering. See "Roof recover" and "Roof replacement."

RESIDENTIAL BUILDING. For this code, ((includes))the following building types are residential buildings:

1. Detached one- and two-family dwellings((,)).

2. Multiple single-family dwellings (townhouses) ((and)).

3. Group ((R-2,)) R-3 ((and R-4))occupancy areas in buildings three stories or less in height above grade plane((, as well as))whose dwelling units are accessed directly from the exterior.

4. Accessory structures ((thereto))to residential buildings.

Group R-2 buildings with dwelling units accessed from interior corridors or other interior spaces are not residential buildings.

ROOF ASSEMBLY. A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly includes the roof covering, underlayment and roof deck, and can also include a thermal barrier, an ignition barrier, insulation or a vapor retarder.

ROOF RECOVER. The process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.

ROOF REPAIR. Reconstruction or renewal of any part of an existing roof for the purposes of its maintenance.

ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.

R-VALUE (THERMAL RESISTANCE). The inverse of the time rate of heat flow through a body from one of its bounding surfaces to the other surface for a unit temperature difference between the two surfaces, under steady state conditions, per unit area (h • ft2 • °F/Btu) [(m2 • K)/W].

Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency and appear in the Register pursuant to the requirements of RCW 34.08.040.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-20220Section R202.20—T.

THERMAL DISTRIBUTION EFFICIENCY (TDE). The resistance to changes in air heat as air is conveyed through a distance of air duct. TDE is a heat loss calculation evaluating the difference in the heat of the air between the air duct inlet and outlet caused by differences in temperatures between the air in the duct and the duct material. TDE is expressed as a percent difference between the inlet and outlet heat in the duct.

THERMAL ISOLATION. Physical and space conditioning separation from conditioned space(s). The conditioned space(s) shall be controlled as separate zones for heating and cooling or conditioned by separate equipment.

THERMOSTAT. An automatic control device used to maintain temperature at a fixed or adjustable set point.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-30310Section R303.1—Identification.

R303.1 Identification. Materials, systems and equipment shall be identified in a manner that will allow a determination of compliance with the applicable provisions of this code.

R303.1.1 Building thermal envelope insulation. An R-value identification mark shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, manufacturer and R-value of insulation installed in each element of the building thermal envelope. For blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density, coverage area and number of bags installed shall be listed on the certification. For sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness shall be listed on the certification. For insulated siding, the R-value shall be labeled on the product's package and shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.

EXCEPTION:

For roof insulation installed above the deck, the R-value shall be labeled as required by the material standards specified in Table 1508.5 of the International Building Code or Table R906.2 of the International Residential Code.

R303.1.1.1 Blown or sprayed roof/ceiling insulation. The thickness of blown-in or sprayed roof/ceiling insulation (fiberglass or cellulose) shall be written in inches (mm) on markers that are installed at least one for every 300 square feet (28 m2) throughout the attic space. The markers shall be affixed to the trusses or joists and marked with the minimum initial installed thickness with numbers a minimum of 1 inch (25 mm) in height. Each marker shall face the attic access opening. Spray polyurethane foam thickness and installed R-value shall be listed on certification provided by the insulation installer.

R303.1.2 Insulation mark installation. Insulating materials shall be installed such that the manufacturer's R-value mark is readily observable upon inspection. For insulation materials that are installed without an observable manufacturer's R-value mark, such as blown or draped products, an insulation certificate complying with Section R303.1.1 shall be left immediately after installation by the installer, in a conspicuous location within the building, to certify the installed R-value of the insulation material.

R303.1.3 Fenestration product rating.U-factors of fenestration products (windows, doors and skylights) shall be determined in accordance with NFRC 100.

EXCEPTION:

Where required, garage door U-factors shall be determined in accordance with either NFRC 100 or ANSI/DASMA 105.

U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by the manufacturer.

Products lacking such a labeled U-factor shall be assigned a default U-factor from Table R303.1.3(1), R303.1.3(2) or R303.1.3(4). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed fenestration products (windows, glazed doors and skylights) shall be determined in accordance with NFRC 200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table R303.1.3(3).

EXCEPTIONS:	1. Units without NFRC ratings produced by a small business may be assigned default U-factors from Table R303.1.3(5) for vertical fenestration.
	2. Owner-built, nonoperable wood frame window consisting of a double pane unit with low-e (E = 0.04 or less), 1/2-inch air space with argon fill.

R303.1.4 Insulation product rating. The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (C.F.R. Title 16, Part 460) in units of h × ft2 × °F/Btu at a mean temperature of 75°F (24°C).

R303.1.4.1 Insulated siding. The thermal resistance (R-value) of insulated siding shall be determined in accordance with ASTM C1363. Installation for testing shall be in accordance with the manufacturer's installation instructions.

R303.1.5 Air-impermeable insulation. Insulation having an air permeability not greater than 0.004 cubic feet per minute per square foot (0.002 L/(s x m2)) under pressure differential of 0.3-inch water gauge (75 Pa) when tested in accordance with ASTM E2178 shall be determined air-impermeable insulation.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-30330Section R303.3—Maintenance information.

R303.3 Maintenance information. Maintenance instructions shall be furnished for equipment and systems that require preventive maintenance. Required regular maintenance actions shall be clearly stated and incorporated on a readily ((accessible))visible label. The label shall include the title or publication number for the operation and maintenance manual for that particular model and type of product.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40100Section R401—General.

R401.1 Scope. This chapter applies to residential buildings. Group R-2 occupancy areas with dwelling units accessed from enclosed interior corridors or other enclosed interior spaces must comply with the Washington State Energy Code (WSEC), Commercial Provisions. Other Group R-2 occupancy areas are permitted to comply with the WSEC, Commercial Provisions, in lieu of the WSEC, Residential Provisions.

EXCEPTION:

Water heaters that each serve only an individual Group R-2 dwelling unit in a building three stories or less above grade plane are permitted to comply with the requirements of the WSEC, Residential Provisions.

R401.2 Compliance. Projects shall comply with one of the following:

1. Sections R401 through R404. In addition, dwelling units and sleeping units in a residential building shall comply with Section R406.

2. Section R405. ((In addition, dwelling units and sleeping units in a residential building shall comply with Section R406.))

3. Section R407.

R401.3 Certificate. A permanent certificate shall be completed by the builder or other approved party and posted on a wall in the space where the furnace is located, a utility room, or an approved location inside the building. When located on an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label, or other required labels. The certificate shall ((list))indicate the following:

1. The predominant R-values of insulation installed in or on ceiling/roof, walls, foundation (slab, below-grade wall, and/or floor) and ducts outside conditioned spaces((;)).

2.U-factors for fenestration and the solar heat gain coefficient (SHGC) of fenestration((;)). Where there is more than one value for each component, the certificate shall indicate the area weighted average value.

3. The results from any required duct system and building envelope air leakage testing done on the building((; and)).

4. The results from the whole-house mechanical ventilation system flow rate test. ((Where there is more than one value for each component, the certificate shall list the value covering the largest area. The certificate shall list))

5. The types, sizes, and efficiencies of heating, cooling, whole-house mechanical ventilation, and service water heating appliances. Where a gas-fired unvented room heater, electric furnace, or baseboard electric heater is installed in the residence, the certificate shall list "gas-fired unvented room heater," "electric furnace" or "baseboard electric heater," as appropriate. An efficiency shall not be listed for gas-fired unvented room heaters, electric furnaces or electric baseboard heaters.

6. Where on-site photovoltaic panel systems have been installed, the array capacity, inverter efficiency, panel tilt, orientation and estimated annual electrical generation shall be noted on the certificate.

7. The code edition under which the structure was permitted, and the compliance path used.

The code official may require that documentation for any required test results include an electronic record of the time, date, and location of the test. A date-stamped smart phone photo or air leakage testing software may be used to satisfy this requirement.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40210Section R402.1—General.

R402.1 General. The building thermal envelope shall meet the requirements of Sections R402.1.1 through R402.1.6.

EXCEPTION:	The following buildings, or portions thereof, separated from the remainder of the building by building thermal envelope assemblies complying with this code shall be exempt from the building thermal envelope provisions of this code.
	1. Those with a peak design rate of energy usage less than 3.4 Btu/h ft2 (10.7 W/m2) or 1.0 watt/ft2 of floor area for space conditioning purposes.
	2. Those that do not contain conditioned space.
	3. Greenhouses isolated from any conditioned space and not intended for occupancy.

R402.1.1 Vapor retarder. Wall assemblies in the building thermal envelope shall comply with the vapor retarder requirements of Section R702.7 of the International Residential Code or Section 1405.3 of the International Building Code, as applicable.

R402.1.2 Insulation and fenestration criteria. The building thermal envelope shall meet the requirements of Table ((R402.1.1))R402.1.2 based on the climate zone specified in Chapter 3. Assemblies shall have a U-factor equal to or less than that specified in Table R402.1.2. Fenestration shall have a U-factor equal to or less than specified in Table R402.1.2.

R402.1.3 R-value alternative. Assemblies with R-value of insulation materials equal to or greater than that specified in Table R402.1.3 shall be an alternative to the U-factor in Table R402.1.2.

((R402.1.2))R402.1.4R-value computation.((Insulation R-value shall be determined as specified in Section R303.1.4. Insulation material used in layers, such as framing cavity insulation or continuous insulation,))Cavity insulation alone shall be used to determine compliance with the cavity insulation R-value requirement in Table R402.1.3. Where cavity insulation is installed in multiple layers, the R-values of the cavity insulation layers shall be summed to ((compute the corresponding component R-value))determine compliance with the cavity insulation R-value requirements. The manufacturer's settled R-value shall be used for blown insulation. Continuous insulation (ci) alone shall be used to determine compliance with the continuous insulation R-value requirements in Table R402.1.3. Where continuous insulation is installed in multiple layers, the R-values of the continuous insulation layers shall be summed to determine compliance with the continuous insulation R-value requirements. Computed R-values shall not include an R-value for other building materials or air films. Where insulated siding is used for the purpose of complying with the continuous insulation requirements of Table ((R402.1.1))R402.1.3, the manufacturer's labeled R-value for insulated siding shall be reduced by R-0.6.

((R402.1.3 U-factor alternative. An assembly with a U-factor equal to or less than that specified in Table R402.1.3 shall be permitted as an alternative to the R-value in Table R402.1.1. U-factors shall be determined as specified in Section R402.1.5.

R402.1.4))R402.1.5 Total UA alternative. If the proposed building thermal envelope UA is less than or equal to the target UA, the building shall be considered in compliance with Table ((R402.1.1))R402.1.2. The proposed UA shall be calculated in accordance with Equation 2. The target UA shall be calculated in accordance with Equation 1. U-factors shall be determined as specified in Section ((R402.1.5))R402.1.6. In addition to UA compliance, the maximum fenestration U-factors of Section R402.5 shall be met.

((R402.1.5))R402.1.6U-factor reference and calculations. The U-factors for typical construction assemblies are included in Appendix A in chapter 51-11C WAC. These values shall be used for all calculations. Where proposed construction assemblies are not represented in Appendix A, values shall be calculated in accordance with the ASHRAE Handbook of Fundamentals using the framing factors listed in Appendix A where applicable and shall include the thermal bridging effects of framing materials. The SHGC requirements shall be met in addition to UA compliance.

Fenestration U-factors shall comply with Section R303.1.3, Fenestration product rating.

((R402.1.6 Vapor retarder. Wall assemblies in the building thermal envelope shall comply with the vapor retarder requirements of Section R702.7 of the International Residential Code or Section 1405.3 of the International Building Code, as applicable.))

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40211Table ((R402.1.1))R402.1.2—Insulation and fenestration requirements by component.

TABLE ((R402.1.1))R402.1.2

INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa

((Climate Zone	Fenestration U-Factorb	Skylightb U-Factor	Ceiling R-Valuee	Wood Frame Wallg, h R-Value	Floor R-Value	Below-Gradec, h Wall R-Value	Slabd, f R-Value & Depth
5 and Marine 4	0.30	0.50	49	21 int	30	10/15/ 21int+5TB	10, 2 ft

For SI:	1 foot = 304.8 mm, ci = continuous insulation, int = intermediate framing.
	aR-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the compressed R-value of the insulation from Appendix Table A101.4 shall not be less than the R-value specified in the table.
	b The fenestration U-factor column excludes skylights.
	c "10/15/21+5TB" means R-10 continuous insulation on the exterior of the wall, or R-15 on the continuous insulation on the interior of the wall, or R-21 cavity insulation plus a thermal break between the slab and the basement wall at the interior of the basement wall. "10/15/21+5TB" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the wall. "TB" means R-5 thermal break between floor slab and basement wall.
	d R-10 continuous insulation is required under heated slab on grade floors. See Section R402.2.9.1.
	e For single rafter- or joist-vaulted ceilings, the insulation may be reduced to R38 if the full insulation depth extends over the top plate of the exterior wall.
	f R-7.5 continuous insulation installed over an existing slab is deemed to be equivalent to the required perimeter slab insulation when applied to existing slabs complying with Section R503.1.1. If foam plastic is used, it shall meet the requirements for thermal barriers protecting foam plastics.
	g For log structures developed in compliance with Standard ICC 400, log walls shall meet the requirements for climate zone 5 of ICC 400.
	h Int. (intermediate framing) denotes framing and insulation as described in Section A103.2.2 including standard framing 16 inches on center, 78 percent of the wall cavity insulated and headers insulated with a minimum of R-10 insulation.))

CLIMATE ZONE 5 AND MARINE 4
Fenestration U-factorb		0.28
Skylight U-factor		0.50
Ceiling U-factor		0.024
Above-Grade Wall U-factor		0.056
Floor U-factor		0.029
Slab on Grade F-factor		0.54
Below Grade 2' Depth
	Wall U-factor	0.042
	Slab F-factor	0.59
Below Grade 3.5' Depth
	Wall U-factor	0.040
	Slab F-factor	0.56
Below Grade 7' Depth
	Wall U-factor	0.035
	Slab F-factor	0.50

a	U-factors or F-factors shall be obtained from measurement, calculation, or an approved source or as specified in Section R402.1.5.
b	A maximum U-factor of 0.32 shall apply to vertical fenestration products installed in buildings located above 4000 feet in elevation above sea level, or in windborne debris regions where protection of openings is required under Section R301.2.1.2 of the International Residential Code.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40213Table R402.1.3—((Equivalent U-factors))Insulation minimum R-values and fenestration requirements by components.

TABLE R402.1.3

((EQUIVALENT U-FACTORSa

Climate Zone 5 and Marine 4
Fenestration U-Factor		0.30
Skylight U-Factor		0.50
Ceiling U-Factor		0.026
Above-Grade Wall U-Factor		0.056
Floor U-Factor		0.029
Slab on Grade F-Factor		0.54
Below Grade 2' Depth
	Wall U-Factor	0.042
	Slab F-Factor	0.59
Below Grade 3.5' Depth
	Wall U-Factor	0.040
	Slab F-Factor	0.56
Below Grade 7' Depth
	Wall U-Factor	0.035
	Slab F-Factor	0.50

aU-factors or F-factors shall be obtained from measurement, calculation or an approved source or as specified in Section R402.1.5.))

INSULATION MINIMUM R-VALUES AND FENESTRATION REQUIREMENTS BY COMPONENTSa

Climate Zone 5 and Marine 4
Fenestrationb,jU-Factor	0.28
SkylightbU-Factor	0.50
CeilingeR-Value	60
Wood Frame Wallg,iR-Value	20+5 or 13+10
Floor R-Value	30
Below-Grade Wallc,hR-Value	10/15/21 int + 5TB
Slabd,fR-Value and Depth	10, 4 ft.

For SI:	1 foot = 304.8 mm, ci = continuous insulation, int = intermediate framing.
	aR-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the compressed R-value of the insulation from Appendix Table A101.4 shall not be less than the R-value specified in the table.
	b The fenestration U-factor column excludes skylights.
	c "10/15/21+5TB" means R-10 continuous insulation on the exterior of the wall, or R-15 on the continuous insulation on the interior of the wall, or R-21 cavity insulation plus a thermal break between the slab and the basement wall at the interior of the basement wall. "10/15/21+5TB" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the wall. "TB" means R-5 thermal break between floor slab and basement wall.
	d R-10 continuous insulation is required under heated slab on grade floors. See Section R402.2.9.1.
	e For single rafter- or joist-vaulted ceilings, the insulation may be reduced to R-38 if the full insulation depth extends over the top plate of the exterior wall.
	f R-7.5 continuous insulation installed over an existing slab is deemed to be equivalent to the required perimeter slab insulation when applied to existing slabs complying with Section R503.1.1. If foam plastic is used, it shall meet the requirements for thermal barriers protecting foam plastics.
	g For log structures developed in compliance with Standard ICC 400, log walls shall meet the requirements for climate zone 5 of ICC 400.
	h Int. (intermediate framing) denotes framing and insulation as described in Section A103.2.2 including standard framing 16 inches on center, 78 percent of the wall cavity insulated and headers insulated with a minimum of R-10 insulation.
	i The first value is cavity insulation, the second value is continuous insulation. Therefore, as an example "13+10" means R-13 cavity insulation plus R-10 continuous insulation.
	j A maximum U-factor of 0.32 shall apply to vertical fenestration products installed in buildings located above 4000 feet in elevation above sea level, or in windborne debris regions where protection of openings is required under Section R301.2.1.2 of the International Residential Code.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40215Target/Proposed UA equations.

EQUATION 1 - GROUP R OCCUPANCY

TARGET UA

UAT = UWAW + UBGWABGW + UVGAVG + UOGAOG + UFAF + URCARC + UDAD + FSPS + FBGSPBGS

Where:
	UAT	=	The target combined thermal transmittance of the gross exterior wall, floor and roof/ceiling area.
	UW	=	The thermal transmittance value of the opaque above grade wall found in Table ((R402.1.3))R402.1.2.
	AW	=	Opaque above grade wall area.
	UBGW	=	The thermal transmittance value of the below grade opaque wall found in Table ((R402.1.3))R402.1.2.
	ABGW	=	Opaque below grade wall area.
	UVG	=	The thermal transmittance value of the fenestration found in Table ((R402.1.3))R402.1.2.
	AVG	=	(a) The proposed glazing area; where proposed fenestration glazing area is less than 15 percent of the conditioned floor area, minus AOG.
			(b) 15 percent of the conditioned floor area; where the proposed fenestration glazing area is 15 percent or more of the conditioned floor area, minus AOG.
	UOG	=	The thermal transmittance value of the skylight glazing found in Table ((R402.1.3))R402.1.2.
	AOG	=	Skylight glazing area (if the proposed AOG exceeds 15 percent, the target AOG shall be 15 percent of the total floor area of the conditioned space).
	UF	=	The thermal transmittance value of the floor found in Table ((R402.1.3))R402.1.2.
	AF	=	Floor area over unconditioned space.
	URC	=	The thermal transmittance value of the ceiling found in Table ((R402.1.3))R402.1.2.
	ARC	=	Roof/ceiling area.
	UD	=	The thermal transmittance value of the fenestration found in Table ((R402.1.3))R402.1.2.
	AD	=	Opaque door area.
	FS	=	Concrete slab on grade component F-factor found in Table ((R402.1.3))R402.1.2.
	PS	=	Lineal ft. of concrete slab on grade perimeter.
	FBGS	=	Concrete below grade slab component F-factor found in Table ((R402.1.3))R402.1.2.
	PBGS	=	Lineal ft. of concrete below grade slab perimeter.

EQUATION 2 - GROUP R OCCUPANCY

PROPOSED UA

UA = UWAW + UBGWABGW + UVGAVG + UOGAOG + UFAF + URCARC + UDAD + FSPS + FBGSPBGS

Where:
	UA	=	The combined thermal transmittance of the gross exterior wall, floor and roof/ceiling assembly area.
	UW	=	The thermal transmittance of the opaque above grade wall area.
	AW	=	Opaque above grade wall area.
	UBGW	=	The thermal transmittance value of the below grade opaque wall.
	ABGW	=	Opaque below grade wall area.
	UVG	=	The thermal transmittance value of the fenestration glazing.
	AVG	=	Fenestration glazing area, including windows in exterior doors.
	UOG	=	The thermal transmittance value of the skylight glazing.
	AOG	=	Skylight glazing area.
	UF	=	The thermal transmittance of the floor.
	AF	=	Floor area over unconditioned space.
	URC	=	The thermal transmittance of the ceiling.
	ARC	=	Ceiling area.
	UD	=	The thermal transmittance value of the opaque door area.
	AD	=	Opaque door area.
	FS	=	Concrete slab on grade component F-factor.
	PS	=	Lineal ft. of concrete slab on grade perimeter.
	FBGS	=	Concrete below grade slab component F-factor.
	PBGS	=	Lineal ft. of concrete below grade slab perimeter.

NOTE:	Where more than one type of wall, window, roof/ceiling, door and skylight is used, the U and A terms for those items shall be expanded into subelements as:
	UW1AW1 + UW2AW2 + UW3AW3 + ...etc.

NOTE:

Below grade walls: The wall is assumed to extend from the slab upward to the top of the mud sill for the distance specified in Table A104.1, with 6 inches of concrete wall extending above grade. This will be calculated separately from above grade walls using the wall height that best describes the system.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-40220Section R402.2—Specific insulation requirements.

R402.2 Specific insulation requirements. In addition to the requirements of Section R402.1, insulation shall meet the specific requirements of Sections R402.2.1 through R402.2.11.

R402.2.1 Ceilings with attic spaces. Where Section ((R402.1.1))R402.1.3 would require ((R-49))R-60 in the ceiling or attic, installing ((R-38))R-49 over 100 percent of the ceiling area requiring insulation shall ((be deemed to)) satisfy the requirement for ((R-49))R-60 wherever the full height of uncompressed ((R-38))R-49 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the ((U-factor alternative approach))insulation and fenestration criteria in Section ((R402.1.3))R402.1.2 and the total UA alternative in Section ((R402.1.4))R402.1.5.

R402.2.1.1 Loose insulation in attic spaces. Open-blown or poured loose fill insulation may be used in attic spaces where the slope of the ceiling is not more than 3 feet in 12 and there is at least 30 inches of clear distance from the top of the bottom chord of the truss or ceiling joist to the underside of the sheathing at the roof ridge.

R402.2.2 Reserved.

R402.2.3 Eave baffle. For air-permeable insulation((s)) in vented attics, a baffle shall be installed adjacent to soffit and eave vents. Baffles shall maintain ((an))a net free area opening equal to or greater than the size of the vent. The baffle shall extend over the top of the attic insulation. The baffle shall be permitted to be any solid material. The baffle shall be installed to the outer edge of the exterior wall top plate so as to provide maximum space for attic insulation coverage over the top plate. Where soffit venting is not continuous, baffles shall be installed continuously to prevent ventilation air in the eave soffit from bypassing the baffle.

R402.2.4 Access hatches and doors. Access hatches and doors from conditioned spaces to unconditioned spaces (((e.g.,))such as attics and crawl spaces(())) shall be ((weatherstripped and)) insulated to ((a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood framed or equivalent baffle or retainer is required to be provided when loose fill insulation is installed, the purpose of which is to prevent the loose fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose fill insulation))the same R-value required by Table R402.1.3 for the wall or ceiling in which they are installed.

EXCEPTION:

Vertical doors ((that provide))providing access from conditioned spaces to unconditioned spaces ((shall be permitted to meet))that comply with the fenestration requirements of Table ((R402.1.1))R402.1.3.

R402.2.4.1 Access hatches and door insulation installation and retention. Vertical or horizontal access hatches and doors from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weatherstripped. Access that prevents damaging or compressing the insulation shall be provided to all equipment. Where loose fill insulation is installed, a wood framed or equivalent baffle or retainer, or dam shall be installed to prevent the loose-fill insulation from spilling into the living spaces, from higher to lower sections of the attic and from attics covering conditioned spaces to unconditioned spaces. The baffle or retainer shall provide a permanent means of maintaining the installed R-value of the loose fill insulation.

R402.2.5 Mass walls. Mass walls, where used as a component of the building thermal envelope((of a building)), shall be one of the following:

1. ((Constructed of))Above-grade walls of concrete block, concrete, insulated concrete form, masonry cavity, brick (but not brick veneer), adobe, compressed earth block, rammed earth, mass timber, ((solid timber)) or solid logs.

2. Any other wall having a heat capacity greater than or equal to 6 Btu/ft2 x °F (123 kJ/m2 x K).

R402.2.6 Steel-frame ceilings, walls, and floors. Steel-frame ceilings, walls, and floors shall comply with the U-factor requirements of Table ((R402.1.3))R402.1.2.

R402.2.7 Floors. Floor framing cavity insulation shall comply with one of the following:

1. Insulation shall be installed to maintain permanent contact with the underside of the subfloor decking in accordance with manufacturer instructions to maintain required R-value or readily fill the available cavity space. Insulation supports shall be installed so spacing is no more than 24 inches on center. Foundation vents shall be placed so that the top of the vent is below the lower surface of the floor insulation.

2. Floor framing cavity insulation shall be permitted to be in contact with the top side of sheathing separating the cavity and the unconditioned space below. Insulation shall extend from the bottom to the top of all perimeter floor framing members and the framing members shall be air sealed.

3. A combination of cavity and continuous insulation shall be installed so that the cavity insulation is in contact with the top side of the continuous insulation that is installed on the underside of the floor framing separating the cavity and the unconditioned space below. The combined R-value of the cavity and continuous insulation shall equal the required R-value for floors. Insulation shall extend from the bottom to the top of all perimeter floor framing members and the framing members shall be air sealed.

EXCEPTIONS:	1. ((The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum Wood Frame Wall R-value in Table R402.1.1 and extends from the bottom to the top of all perimeter floor framing members.
	2.)) When foundation vents are not placed so that the top of the vent is below the lower surface of the floor insulation, a permanently attached baffle shall be installed at an angle of 30° from horizontal, to divert air flow below the lower surface of the floor insulation.
	((3.))2. Substantial contact with the surface being insulated is not required in enclosed floor/ceiling assemblies containing ducts where full R-value insulation is installed between the duct and the exterior surface.

R402.2.8 Below-grade walls. Below-grade exterior wall insulation used on the exterior (cold) side of the wall shall extend from the top of the below-grade wall to the top of the footing and shall be approved for below-grade use. Above-grade insulation shall be protected. Insulation used on the interior (warm) side of the wall shall extend from the top of the below-grade wall to the below-grade floor level and shall include R-5 rigid board providing a thermal break between the concrete wall and the slab.

R402.2.9 Slab-on-grade floors. The minimum thermal resistance (R-value) of the insulation around the perimeter of unheated or heated slab-on-grade floors shall be as specified in Table ((C402.1.1))C402.1.3. The insulation shall be placed on the outside of the foundation or on the inside of the foundation wall. The insulation shall extend downward from the top of the slab for a minimum distance as shown in the table or to the top of the footing, whichever is less, or downward to at least the bottom of the slab and then horizontally to the interior or exterior for the total distance shown in the table. A two-inch by two-inch (maximum) pressure treated nailer may be placed at the finished floor elevation for attachment of interior finish materials. Insulation extending away from the building shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil.

R402.2.9.1 Heated slab-on-grade floors. The entire area of a heated slab-on-grade floor shall be thermally isolated from the soil with a minimum of R-10 insulation. The insulation shall be an approved product for its intended use. If a soil gas control system is present below the heated slab-on-grade floor, which results in increased convective flow below the heated slab-on-grade floor, the heated slab-on-grade floor shall be thermally isolated from the sub-slab gravel layer. R-10 heated slab-on-grade floor insulation is required for all compliance paths.

R402.2.10 Masonry veneer. Insulation shall not be required on the horizontal portion of the foundation that supports a masonry veneer.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40230Section R402.3—Fenestration.

R402.3 Fenestration. In addition to the requirements of Section R402, fenestration shall comply with Sections R402.3.1 through R402.3.5.

R402.3.1 U-factor. An area-weighted average of fenestration products shall be permitted to satisfy the U-factor requirements.

R402.3.2 Glazed fenestration SHGC. An area-weighted average of fenestration products more than 50 percent glazed shall be permitted to satisfy the SHGC requirements.

R402.3.3 Glazed fenestration exemption. Up to 15 square feet (1.4 m2) of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in Section ((R402.1.1))R402.1.2. This exemption shall not apply to the ((U-factor alternative approach in Section R402.1.3 and the)) total UA alternative in Section ((R402.1.4))R402.1.5.

R402.3.4 Opaque door exemption. One side-hinged opaque door assembly up to 24 square feet (2.22 m2) in area is exempted from the U-factor requirement in Section ((R402.1.1))R402.1.2. This exemption shall not apply to ((the U-factor alternative approach in Section R402.1.3 and)) the total UA alternative in Section ((R402.1.4))R402.1.5.

R402.3.5 ((Reserved.))Combustion air openings. In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to open combustion, space conditioning fuel burning appliances, the appliances and combustion air openings shall be located outside of the building thermal envelope, or enclosed in a room isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table R402.1.3, where the walls, floors, and ceilings shall meet the minimum of the below-grade wall R-value requirements. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it passes through conditioned space to a minimum of R-8.

EXCEPTIONS:	1. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
	2. Fireplaces and stoves complying with Sections R402.3.6 and R1006 of the International Residential Code.

R402.3.6 Fireplaces. New wood-burning fireplaces shall have tight-fitting flue dampers or doors, and outdoor combustion air. When using tight-fitting doors on factory-built fireplaces listed and labeled in accordance with UL 127, the doors shall be tested and listed for the fireplace. Where using tight-fitting doors on masonry fireplaces, the doors shall be listed and labeled in accordance with UL 907. Gas fireplaces shall comply with the efficiency requirements in Section R403.7.2.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-40240Section R402.4—Air leakage.

R402.4 Air leakage. The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections R402.4.1 through ((R402.4.4))R402.4.5.

R402.4.1 Building thermal envelope air leakage. The building thermal envelope shall comply with Sections R402.4.1.1 ((and R402.4.1.2))through R402.4.1.3. The sealing methods between dissimilar materials shall allow for differential expansion and contraction.

R402.4.1.1 Installation. The components of the building thermal envelope as listed in Table R402.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria listed in Table R402.4.1.1, as applicable to the method of construction. Where required by the code official, an approved third party shall inspect all components and verify compliance.

R402.4.1.2 Testing. The building or dwelling unit shall be tested ((and verified as having an air leakage rate of not exceeding 5 air changes per hour. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). For this test only, the volume of the home shall be the conditioned floor area in ft2 (m2) multiplied by 8.5 feet (2.6 m). Where required by the code official, testing shall be conducted by an approved third party.))for air leakage. Testing shall be conducted in accordance with RESNET/ICC 380, ASTM E779 or ASTM E1827. Test pressure and leakage rate shall comply with Section R402.1.3. A written report of the test results, including verified location and time stamp of the date of the test, shall be signed by the ((party conducting the test))testing agency and provided to the building owner andcode official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope. Once visual inspection has confirmed air sealing (((see))has been conducted in accordance with Table R402.4.1.1(())), operable windows and doors manufactured by small business((shall be))are permitted to be sealed off at the frame prior to the test.

((EXCEPTION:

For dwelling units that are accessed directly from the outdoors, other than detached one family dwellings and townhouses, an air leakage rate not exceeding 0.4 cfm per square foot of the dwelling unit enclosure area shall be an allowable alternative. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals) in accordance with RESNET/ICC 380, ASTM E779 or ASTM E1827. For the purpose of this test only, the enclosure area is to be calculated as the perimeter of the dwelling unit, measured to the outside face of the exterior walls, and the centerline of party walls, times 8.5 feet, plus the ceiling and floor area. Doors and windows of adjacent dwelling units (including top and bottom units) shall be open to the outside during the test. This exception is not permitted for dwelling units that are accessed from corridors or other enclosed common areas.))

Testing of single-family dwellings and townhouses shall be conducted in accordance with RESNET/ICC 380. Test pressure and leakage rate shall comply with Section R402.1.3.1.

For Group R-2 occupancies, testing shall be conducted in accordance with ASTM E779, ASTM E1827, or ASTM E3158. Test pressure and leakage rate shall comply with Section R402.1.3.2. The individual performing the air leakage test shall be trained and certified by a certification body that is, at the time of permit application, and ISO 17024 accredited certification body including, but not limited to, the Air Barrier Association of America.

During testing:

1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures;

2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures;

3. Interior doors, if installed at the time of the test, shall be open, access hatches to conditioned crawl spaces and conditioned attics shall be open;

4. Exterior or interior terminations for continuous ventilation systems and heat recovery ventilators shall be sealed;

5. Heating and cooling systems, if installed at the time of the test, shall be turned off; and

6. Supply and return registers, if installed at the time of the test, shall be fully open.

EXCEPTION((S)):	((1.)) Additions less than 500 square feet of conditioned floor area.
	((2. Additions tested with the existing home having a combined maximum air leakage rate of 7 air changes per hour. To qualify for this exception, the date of construction of the existing house must be prior to the 2009 Washington State Energy Code.))

((R402.4.2 Fireplaces. New wood-burning fireplaces shall have tight-fitting flue dampers or doors, and outdoor combustion air. When using tight-fitting doors on factory-built fireplaces listed and labeled in accordance with UL 127, the doors shall be tested and listed for the fireplace. Where using tight-fitting doors on masonry fireplaces, the doors shall be listed and labeled in accordance with UL 907.

R402.4.2.1 Gas fireplace efficiency. All vented gas fireplace heaters rated to ANSI Z21.88 shall be listed and labeled with a fireplace efficiency (FE) rating of 50 percent or greater in accordance with CSA P.4.1. Vented gas fireplaces (decorative appliances) certified to ANSI Z21.50 shall be listed and labeled, including their FE ratings, in accordance with CSA P.4.1.))

R402.4.1.3 Leakage rate. Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) shall comply with Section R402.4.1.3.1. Group R-2 multifamily buildings shall comply with Section R402.4.1.3.2.

R402.4.1.3.1 Dwelling unit leakage rate. The maximum air leakage rate for any dwelling unit under any compliance path shall not exceed 3.0 air changes per hour. Testing shall be conducted with a blower door test at a test pressure of 0.2 inches w.g. (50 Pa).

EXCEPTION:

Additions tested with the existing home having a combined maximum air leakage rate of 7 air changes per hour. To qualify for this exception, the date of construction of the existing dwelling must be prior to the 2009 Washington State Energy Code.

R402.4.1.3.2 Group R-2 multifamily building leakage rate. For Group R-2 multifamily buildings, the maximum leakage rate for any dwelling unit shall not exceed 0.25 cfm per square foot of the dwelling unit enclosure area. Testing shall be conducted with a blower door at a test pressure of 0.2 inches w.g. (50 Pa). Doors and windows of adjacent dwelling units (including top and bottom units) shall be open to the outside during the test.

R402.4.3 Air leakage of fenestration. Windows, skylights and sliding glass doors shall have an air infiltration rate of no more than 0.3 cfm per square foot (1.5 L/s/m2), and swinging doors no more than 0.5 cfm per square foot (2.6 L/s/m2), when tested according to NFRC 400 or AAMA/WDMA/CSA 101/I.S.2/A440 by an accredited, independent laboratory and listed and labeled by the manufacturer.

EXCEPTIONS:	1. Field-fabricated fenestration products (windows, skylights and doors).
	2. Custom exterior fenestration products manufactured by a small business provided they meet the applicable provisions of Chapter 24 of the International Building Code. Once visual inspection has confirmed the presence of a gasket, operable windows and doors manufactured by small business shall be permitted to be sealed off at the frame prior to the test.

((R402.4.4Combustion air openings. In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to open combustion, space conditioning fuel burning appliances, the appliances and combustion air openings shall be located outside of the building thermal envelope, or enclosed in a room isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table R402.1.1, where the walls, floors and ceilings shall meet the minimum of the below-grade wall R-value requirement. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it passes through conditioned space to a minimum of R-8.

EXCEPTIONS:	1. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
	2. Fireplaces and stoves complying with Section R402.4.2 and Section R1006 of the International Residential Code.))

R402.4.5 Recessed lighting. Recessed luminaires installed in the building thermal envelope shall be Type IC-rated and certified under ASTM E283 as having an air leakage rate not more than 2.0 cfm (0.944 L/s) when tested at a 1.57 psf (75 Pa) pressure differential and shall have a label attached showing compliance with this test method. All recessed luminaires shall be sealed with a gasket or caulk between the housing and the interior wall or ceiling covering.

R402.4.6 Electrical and communication outlet boxes (air-sealed boxes). Electrical and communication outlet boxes installed in the building thermal envelope shall be sealed to limit air leakage between conditioned and unconditioned spaces. Electrical and communication outlet boxes shall be tested in accordance with NEMA OS 4, Requirements for Air-Sealed Boxes for Electrical and Communication Applications, and shall have an air leakage rate of not greater than 2.0 cubic feet per minute (0.944 L/s) at a pressure differential of 1.57 psf (75 Pa). Electrical and communication outlet boxes shall be marked "NEMA OS 4" or "OS 4" in accordance with NEMA OS 4. Electrical and communication outlet boxes shall be installed per the manufacturer's instructions and with any supplied components required to achieve compliance with NEMA OS 4.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40241Table R402.4.1.1—Air barrier and insulation installation.

TABLE R402.4.1.1

AIR BARRIER, AIR SEALING AND INSULATION INSTALLATIONa

COMPONENT	AIR BARRIER CRITERIA((a))	INSULATION CRITERIA((a))
General requirements	A continuous air barrier shall be installed in the building envelope.	Air-permeable insulation shall not be used as a sealing material.
	((Exterior thermal envelope contains a continuous air barrier.))
	Breaks or joints in the air barrier shall be sealed.
Cavity insulation installation		All cavities in the thermal envelope shall be filled with insulation. The density of the insulation shall be at the manufacturers' product recommendation and said density shall be maintained for all volume of each cavity. Batt type insulation will show no voids or gaps and maintain an even density for the entire cavity. Batt insulation shall be installed in the recommended cavity depth. Where an obstruction in the cavity due to services, blocking, bracing or other obstruction exists, the batt product will be cut to fit the remaining depth of the cavity. Where the batt is cut around obstructions, loose fill insulation shall be placed to fill any surface or concealed voids, and at the manufacturers' specified density. Where faced batt is used, the installation tabs must be stapled to the face of the stud. There shall be no compression to the batt at the edges of the cavity due to inset stapling installation tabs.
Cavity insulation installation		Insulation that upon installation readily conforms to available space shall be installed filling the entire cavity and within the manufacturers' density recommendation.
Ceiling/attic	The air barrier in any dropped ceiling/soffit shall be aligned with the insulation and any gaps in the air barrier sealed.	The insulation in any dropped ceiling/soffit shall be aligned with the air barrier.
Ceiling/attic	Access openings, drop down stair or knee wall doors to unconditioned attic spaces shall be sealed.	Batt insulation installed in attic roof assemblies may be compressed at exterior wall lines to allow for required attic ventilation.
Walls	The junction of the foundation and sill plate shall be sealed. The junction of the top plate and top of exterior walls shall be sealed. Knee walls shall be sealed.	Cavities within corners and headers of frame walls shall be insulated by completely filling the cavity with a material having a thermal resistance of R-3 per inch minimum. Exterior thermal envelope insulation for framed walls shall be installed in substantial contact and continuous alignment with the air barrier.
Windows, skylights and doors	The space between window/door jambs and framing and skylights and framing shall be sealed.
Rim joists	Rim joists shall include ((the))an exterior air barrierb.	Rim joists shall be insulated so that the insulation maintains permanent contact with the exterior rim boardb.
	The junctions of the rim board to the sill plate and the rim board and the subfloor shall be air sealed.
Floors (including above garage and cantilevered floors)	The air barrier shall be installed at any exposed edge of insulation.	Floor framing cavity insulation shall be installed to maintain permanent contact with the underside of subfloor decking or floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the underside of floor framing and extend from the bottom to the top of all perimeter floor framing members.
Basement, crawl space ((walls)), and slab foundations	Exposed earth in unvented crawl spaces shall be covered with a Class I, black vapor retarder with overlapping joints taped.	((Where provided instead of floor insulation, insulation shall be permanently attached to the crawlspace walls.))Crawl space insulation, where provided instead of floor insulation, shall be installed in accordance with Section R402.2.10.
	Penetrations through concrete foundation walls and slabs shall be air sealed.	Conditioned basement foundation wall insulation shall be installed in accordance with Section R402.2.8.1.
	Class I vapor retarders shall not be used as an air barrier on below-grade walls and shall be installed in accordance with Section R702.7 of the International Residential Code.	Slab on grade floor insulation shall be installed in accordance with Section R402.2.10.
Shafts, penetrations	Duct ((shafts, utility penetrations,)) and flue shafts ((opening)) to exterior or unconditioned space shall be air sealed.	Insulation shall be fitted tightly around utilities passing through shafts and penetrations in the building thermal envelope to maintain required R-value.
	Utility penetrations of the air barrier shall be caulked, gasketed, or otherwise sealed and shall allow for expansion and contraction of materials and mechanical vibration.
Narrow cavities	Narrow cavities, of an inch or less, not able to be insulated, shall be air sealed.	Batts in narrow cavities shall be cut to fit and installed to the correct density without any voids or gaps or compression, or narrow cavities shall be filled by insulation that on installation readily conforms to the available cavity space.
Garage separation	Air sealing shall be provided between the garage and conditioned spaces.	Insulated portions of the garage separation assembly shall be installed in accordance with Sections R303 and R402.2.8.
Recessed lighting	Recessed light fixtures installed in the building thermal envelope shall be air sealed ((to the finished surface))in accordance with Section R402.4.5.	Recessed light fixtures installed in the building thermal envelope shall be air tight and IC rated and shall be buried or surrounded with insulation.
Plumbing ((and)), wiring, or other obstructions	All holes created by wiring, plumbing, or other obstructions in the air barrier assembly shall be air sealed.	Batt insulation shall be cut neatly to fit around wiring and plumbing in exterior walls. There shall be no voids or gaps or compression where cut to fit. Insulation that on installation readily conforms to available space shall extend behind piping and wiring. Insulation shall be installed to fill the available space and surround wiring, plumbing, or other obstructions, unless the required R-value can be met by installing insulation and air barrier systems completely to the exterior side of the obstructions.
Shower/tub on exterior wall	The air barrier installed at exterior walls adjacent to showers and tubs shall separate the wall from the showers and tubs.	Exterior walls adjacent to showers and tubs shall be insulated.
Electrical/phone box on exterior wall	The air barrier shall be installed behind electrical or communication boxes or air sealed boxes shall be installed.
HVAC register boots	HVAC supply and return register boots shall be sealed to the subfloor, wall covering or ceiling penetrated by the boot.
Concealed sprinklers	When required to be sealed, concealed fire sprinklers shall only be sealed in a manner that is recommended by the manufacturer. Caulking or other adhesive sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.

IC = insulation contact.

a In addition, inspection of log walls shall be in accordance with the provisions of ICC-400.

b Insulation installed in unconditioned/ventilated attic spaces is not required to be enclosed within an air barrier assembly.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40250Section R402.5—Maximum fenestration U-factor and SHGC.

R402.5 Maximum fenestration U-factor. The area-weighted average maximum fenestration U-factor permitted using tradeoffs from Section ((R402.1.4))R402.1.5 or R405 shall be 0.48 for vertical fenestration, and 0.75 for skylights.

EXCEPTION:

The maximum U-factor and solar heat gain coefficient (SHGC) for fenestration shall not be required in storm shelters complying with ICC 500.

AMENDATORY SECTION(Amending WSR 22-13-100, filed 6/14/22, effective 7/15/22)

WAC 51-11R-40310Section R403.1—Controls.

R403.1 Controls.((At least))Not less than one thermostat shall be provided for each separate heating and cooling system.

R403.1.1 Programmable or connected thermostat. Where the primary heating system is a forced-air furnace, at least one thermostat per dwelling unit shall be Energy Star certified and capable of controlling the heating and cooling system on a daily schedule to maintain different temperature set points at different times of the day and different days of the week. The thermostat shall allow for, at a minimum, a 5-2 programmable schedule (weekdays/weekends) and be capable of providing at least two programmable setback/setup periods per day. This thermostat shall include the capability to set back, set up or temporarily operate the system to maintain zone temperatures down to 55°F (13°C) or up to 85°F (29°C). The thermostat shall ((initially)) be programmed initially by the manufacturer with a heating temperature set point ((no higher))of not greater than 70°F (21°C) and a cooling temperature set point ((no lower))of not less than 78°F (26°C). The thermostat and/or control system shall have an adjustable deadband of not less than 10°F.

EXCEPTIONS:	1. Systems controlled by an occupant sensor that is capable of shutting the system off when no occupant is sensed for a period of up to 30 minutes.
	2. Systems controlled solely by a manually operated timer capable of operating the system for no more than two hours.
	3. Ductless mini-split heat pump systems that have an integral proprietary thermostat.

R403.1.2 Heat pump supplementary heat. Unitary air cooled heat pumps shall include controls that minimize supplemental heat usage during start-up, set-up, and defrost conditions. These controls shall anticipate need for heat and use compression heating as the first stage of heat. Controls shall indicate when supplemental heating is being used through visual means (e.g., LED indicators). Heat pumps equipped with supplementary heaters shall be installed with controls that prevent supplemental heater operation above 40°F. At final inspection the auxiliary heat lock out control shall be set to 35°F or less.

R403.1.3 Continuously burning pilot lights. The natural gas systems and equipment listed below are not permitted to be equipped with continuously burning pilot lights.

1. Fan-type central furnaces.

2. Household cooking appliances.

EXCEPTION:

Household cooking appliances without electrical supply voltage connections and in which each pilot light consumes less than 150 Btu/hr.

3. Pool heaters.

4. Spa heaters.

5. ((Beginning September 1, 2022,))Fireplaces.

EXCEPTION:

Any fireplace with on-demand, intermittent or interrupted ignition (as defined in ANSI Z21.20) is not considered continuous.

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-40315Section R403.2—Hot water boiler.

R403.2 Hot water boiler ((outdoor)) temperature ((setback))reset.((Hot water boilers that supply heat to the building through one- or two-pipe heating systems shall have an outdoor temperature setback control that lowers the boiler water temperature based on the outdoor temperature.))The manufacturer shall configure each gas, oil, and electric boiler (other than a boiler equipped with a tankless domestic water heating coil) with an automatic means of adjusting the water temperature supplied by the boiler to ensure incremental change of the inferred heat load will cause an incremental change in the temperature of the water supplied by the boiler. This can be accomplished with outdoor reset, indoor reset, or water temperature sensing.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40320Section R403.3—Ducts.

R403.3 Ducts. Ducts and air handlers shall be installed in accordance with Sections R403.3.1 through R403.3.7.

R403.3.1 ((Insulation. Ducts outside the building thermal envelope shall be insulated to a minimum of R-8. Ducts within a concrete slab or in the ground shall be insulated to R-10 with insulation designed to be used below grade))Ducts located outside conditioned space. Supply and return ducts located outside conditioned space shall be insulated to and R-value of not less than R-8 for ducts 3 inches (76 mm) in diameter and larger and not less than R-6 for ducts smaller than 3 inches (76 mm) in diameter. Ducts buried beneath a building shall be insulated as required per this section or have an equivalent thermal distribution efficiency. Ducts within a concrete slab or in the ground shall be insulated to R-10 with insulation designed to be used below grade. Underground ducts utilizing the thermal distribution efficiency method shall be listed and labeled to indicate the R-value equivalency.

((EXCEPTION:

Ducts or portions thereof located completely inside the building thermal envelope. Ducts located in crawl spaces do not qualify for this exception.))

R403.3.2 Ducts located in conditioned space. For ducts to be considered as being located inside a conditioned space, such ducts shall comply with the following:

1. All duct systems shall be located completely within the continuous air barrier and within the building thermal envelope.

2. All heating, cooling, and ventilation system components shall be installed inside the conditioned space including, but not limited to, forced air ducts, hydronic piping, hydronic floor heating loops, convectors and radiators. Combustion equipment shall be direct vent or sealed combustion.

3. For forced air ducts, a maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts is permitted to be located outside the conditioned space, provided they are insulated to a minimum of R-8.

3.1. Metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic.

3.2. If flex ducts are used, they cannot contain splices. Flex duct connections must be made with nylon straps and installed using a plastic strapping tensioning tool.

4. Ductwork in floor cavities located over unconditioned space shall comply with all of the following:

4.1. A continuous air barrier installed between unconditioned space and the duct.

4.2. Insulation installed in accordance with Section R402.2.7.

4.3. A minimum R-19 insulation installed in the cavity width separating the duct from unconditioned space.

5. Ductwork located within exterior walls of the building thermal envelope shall comply with the following:

5.1. A continuous air barrier installed between unconditioned space and the duct.

5.2. A minimum R-10 insulation installed in the cavity width separating the duct from unconditioned space.

5.3. The remainder of the cavity insulation shall be fully insulated to the drywall side.

R403.3.3 Ducts buried within ceiling insulation. Where supply and return air ducts are partially or completely buried in ceiling insulation, such ducts shall comply with all of the following:

1. The supply and return ducts shall have an insulation R-value not less than R-8.

2. At all points along each duct, the sum of the ceiling insulation R-value against and above the top of the duct, and against and below the bottom of the duct, shall be not less than R-19, excluding the R-value of the duct insulation.

EXCEPTION:

Sections of the supply duct that are less than 3 feet (914 mm) from the supply outlet shall not be required to comply with these requirements.

R403.3.3.1 Effective R-value of deeply buried ducts. Where using a simulated energy performance analysis, sections of ducts that are: Installed in accordance with Section R403.3.3; located directly on, or within 5.5 inches (140 mm) of the ceiling; surrounded with blown-in attic insulation having an R-value of R-30 or greater and located such that the top of the duct is not less than 3.5 inches (89 mm) below the top of the insulation, shall be considered as having an effective duct insulation R-value of R-25.

R403.3.4 Sealing. Ducts, air handlers, and filter boxes shall be sealed. Joints and seams shall comply with either the International Mechanical Code or International Residential Code, as applicable.

EXCEPTIONS:	1. Air-impermeable spray foam products shall be permitted to be applied without additional joint seals.
	2. For ducts having a static pressure classification of less than 2 inches of water column (500 Pa), additional closure systems shall not be required for continuously welded joints and seams, and locking-type joints and seams of other than the snap-lock and button-lock types.

((R403.3.2.1))R403.3.4.1 Sealed air handler and location. Air handlers shall have a manufacturer's designation for an air leakage of no more than 2 percent of the design air flow rate when tested in accordance with ASHRAE 193. Air handlers shall be located in the conditioned space.

((R403.3.3))R403.3.5 Duct testing. Ducts shall be leak tested in accordance with WSU RS-33, using the maximum duct leakage rates specified.

EXCEPTION((S)):

((1. The total leakage or leakage to the outdoors test is not required for ducts and air handlers located entirely within the building thermal envelope. For forced air ducts, a maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts may be located outside the conditioned space. All metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic. If flex ducts are used, they cannot contain splices. Flex duct connections must be made with nylon straps and installed using a plastic strapping tensioning tool. Ducts located in crawl spaces do not qualify for this exception.

2.)) A duct air leakage test shall not be required for ducts serving ((heat or energy recovery ventilators))ventilation systems that are not integrated with the ducts serving heating or cooling systems.

A written report of the results shall be signed by the party conducting the test and provided to the code official.

((R403.3.4))R403.3.6 Duct leakage. The total leakage of the ducts, where measured in accordance with Section R403.3.3, shall be as follows:

1. Rough-in test: Total leakage shall be less than or equal to ((4))4.0 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure. All registers shall be taped or otherwise sealed during the test. If the air handler is not installed at the time of the test, total leakage shall be less than or equal to ((3))3.0 cfm (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.

2. Postconstruction test: Leakage to outdoors shall be less than or equal to ((4))4.0 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area or total leakage shall be less than or equal to ((4))4.0 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure. All register boots shall be taped or otherwise sealed during the test.

3. Test for ducts within thermal envelope: Where all ducts and air handlers are located entirely within the building thermal envelope, total leakage shall be less than or equal to 8.0 cubic feet per minute (226.6 L/min) per 100 square feet (9.29 m2) of conditioned floor area. For forced air ducts, a maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts may be located outside the conditioned space. All metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic. If flex ducts are used, they cannot contain splices. Flex duct connections must be made with nylon straps and installed using a plastic strapping tensioning tool. Ducts located in crawl spaces do not qualify for this exception.

((R403.3.5))R403.3.7 Building cavities. Building framing cavities shall not be used as ducts or plenums. Installation of ducts in exterior walls, floors or ceilings shall not displace required envelope insulation.

((R403.3.6 Ducts buried within ceiling insulation. Where supply and return air ducts are partially or completely buried in ceiling insulation, such ducts shall comply with all of the following:

1. The supply and return ducts shall have an insulation R-value not less than R-8.

EXCEPTION:

Sections of the supply duct that are less than 3 feet (914 mm) from the supply outlet shall not be required to comply with these requirements.

R403.3.6.1 Effective R-value of deeply buried ducts. Where using a simulated energy performance analysis, sections of ducts that are: Installed in accordance with Section R403.3.6; located directly on, or within 5.5 inches (140 mm) of the ceiling; surrounded with blown-in attic insulation having an R-value of R-30 or greater and located such that the top of the duct is not less than 3.5 inches (89 mm) below the top of the insulation, shall be considered as having an effective duct insulation R-value of R-25.

R403.3.7 Ducts located in conditioned space. For ducts to be considered as being located inside a conditioned space, such ducts shall comply with the following:

1. All duct systems shall be located completely within the continuous air barrier and within the building thermal envelope.

2. All heating, cooling and ventilation system components shall be installed inside the conditioned space including, but not limited to, forced air ducts, hydronic piping, hydronic floor heating loops, convectors and radiators. Combustion equipment shall be direct vent or sealed combustion.

3.1. Metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic.

3.2. If flex ducts are used, they cannot contain splices. Flex duct connections must be made with nylon straps and installed using a plastic strapping tensioning tool.))

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40330Section R403.4—Mechanical system piping insulation.

R403.4 Mechanical system piping insulation. Mechanical system piping capable of carrying fluids above 105°F (41°C) or below 55°F (13°C) shall be insulated to a minimum of R-6.

EXCEPTION:

Up to 200 feet of hydronic system piping installed within the conditioned space may be insulated with a minimum of 1/2-inch insulation with a k value of 0.28.

R403.4.1 Protection of piping insulation. Piping insulation, including termination ends, exposed to weather shall be protected from damage, including that caused by sunlight, moisture, ((equipment maintenance))physical damage, and wind, and shall provide shielding from solar radiation that can cause degradation of the material. Protection shall be removable for the exposed length or no less than six inches from the equipment for maintenance. Adhesive tape shall not be permitted.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40340Section R403.5—Service hot water systems.

R403.5 Service hot water systems. Energy conservation measures for service hot water systems shall be in accordance with ((Sections R403.5.1 through R403.5.5))this section. Service water-heating equipment shall meet the requirements of DOE 10 C.F.R. Part 430 Uniform Energy Factor or the equipment shall meet the requirements of Section C404.2.

R403.5.1 Heated water circulation and temperature maintenance systems. Heated water circulation systems shall be in accordance with Section R403.5.1.1. Heat trace temperature maintenance systems shall be in accordance with Section R403.5.1.2. Automatic controls, temperature sensors and pumps shall be ((accessible))in a location with access. Manual controls shall be ((readily accessible))in a location with ready access.

R403.5.1.1 Circulation systems. Heated water circulation systems shall be provided with a circulation pump. The system return pipe shall be a dedicated return pipe ((or a cold water supply pipe)). Gravity and thermo-syphon circulation systems ((shall be))are prohibited. Controls ((for circulating hot water system pumps shall start the pump based on the identification of a demand for hot water within the occupancy. The controls shall)) automatically turn off the circulation pump when the water in the circulation loop is at the desired temperature and when there is no demand for hot water.

R403.5.1.1.1 Demand recirculation water systems serving an individual dwelling unit.Demand recirculation water systems shall have controls that start the pump upon receiving a signal from the action of a user of a fixture or appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a fixture fitting or appliance.

R403.5.1.2 Heat trace systems. Electric heat trace systems shall comply with IEEE 515.1 or UL 515. Controls for such systems shall automatically adjust the energy input to the heat tracing to maintain the desired water temperature in the piping in accordance with the times when heated water is used in the occupancy.

R403.5.2 ((Demand recirculation water systems.Demand recirculation water systems shall have controls that comply with both of the following:

1. The controls shall start the pump upon receiving a signal from the action of a user of a fixture or appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a fixture fitting or appliance.

2. The controls shall limit the temperature of the water entering the cold water piping to not greater than 104ºF (40ºC).))Water volume determination. The volume shall be the sum of the internal volumes of pipe, fittings, valves, meters, and manifolds between the nearest source of heated water and the termination of the fixture supply pipe. Water heaters, circulating water systems, and heat trace temperature maintenance systems shall be considered to be sources of heated water. The volume in the piping shall be determined from Table C404.3.1 in the Washington State Energy Code, Commercial Provisions or Table L502.7 of the Uniform Plumbing Code. The volume contained within fixture shutoff valves, within flexible water supply connectors to a fixture fitting and within a fixture fitting shall not be included in the water volume determination. Where heated water is supplied by a recirculating system or heat-traced piping, the volume shall include the portion of the fitting on the branch pipe that supplies water to the fixture.

R403.5.3 Hot water pipe insulation. Insulation for service hot water pipe, both within and outside the conditioned space, shall have a minimum thermal resistance (R-value) of R-3.

EXCEPTION:

Pipe insulation is permitted to be discontinuous where it passes through studs, joists or other structural members and where the insulated pipes pass other piping, conduit or vents, provided the insulation is installed tight to each obstruction.

R403.5.4 Drain water heat recovery units. Drain water heat recovery units shall comply with CSA 55.2 or IAPMO PS 92. Drain water heat recovery units shall be in accordance with CSA 55.1 or IAPMO IGC 346-2017.

R403.5.5 Water heater installation location. Service hot water systems shall be installed within the building thermal envelope.

EXCEPTION:

Where the hot water system efficiency is greater than or equal to 2.0 UEF.

R403.5.6 Electric water heater insulation. All electric water heaters in unconditioned spaces, or on concrete floors in conditioned spaces, shall be placed on an insulated surface with a minimum thermal resistance of R-10, and a minimum compressive strength of 40 psi or engineered to support the appliance.

R403.5.7 Heat pump water heating. Service hot water in one- and two-family dwellings and multiple single-family dwellings (townhouses) shall be provided by a heat pump system. The heat pump water heating system shall be sized to provide 100 percent of peak hot water demand. Where the heat pump is located in unconditioned space, the heat pump water heating system shall be sized to provide 100 percent of peak hot water demand at an entering source dry bulb (or wet bulb if rated for wet bulb temperatures) air temperature of 40°F (4°C).

EXCEPTIONS:	1. Resistance heating elements integrated into heat pump equipment.
	2. Electric water heaters with a rated water storage volume of no greater than 20 gallons.
	3. Dwelling units with no more than 1,000 square feet of conditioned floor area.
	4. Supplementary water heating systems in accordance with Section R403.5.7.1, provided the system capacity does not exceed the capacity of the heat pump water heating system.
	5. Solar water heating systems.
	6. Waste heat and energy recovery systems.
	7. Heat trace freeze protection systems.
	8. Snow and ice melt systems.

R403.5.7.1 Supplementary heat for heat pump water heating systems. Heat pumps used for water heating and having supplementary water heating equipment shall have controls that limit supplementary water heating equipment operation to only those times when one of the following applies:

1. The heat pump water heater cannot meet hot water demand.

2. For heat pumps located in unconditioned space, the outside air temperature is below 40°F (4°C).

3. The heat pump is operating in defrost mode.

4. The vapor compression cycle malfunctions or loses power.

EXCEPTION:

Heat trace temperature maintenance systems, provided the system capacity does not exceed the capacity of the heat pump water heating system.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40350Section R403.6—Mechanical ventilation.

R403.6 Mechanical ventilation. The buildings complying with Section R402.4.1 shall be provided with mechanical ventilation that meets the requirements of Section M1505 in the International Residential Code or Section 403 in theInternational Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

R403.6.1 Whole-house mechanical ventilation system fan efficacy. Mechanical ventilation system fans shall meet the efficacy requirements of Table R403.6.1 at one or more rating points. Fans shall be tested in accordance with HVI 916 and listed. The airflow shall be reported in the product listing or on the label. Fan efficacy shall be reported in the product listing or shall be derived from the input power and airflow values reported in the product listing on the label. Fan efficacy for fully ducted HRV, ERV, balanced, and in-line fans shall be determined at a static pressure of not less than 0.2 inch w.c. (49.85 Pa). Fan efficacy for ducted range hoods, bathroom and utility room fans shall be determined at a static pressure of not less than 0.1 inch w.c. (24.91 Pa).

((EXCEPTION:

Where an air handler that is integral to the tested and listed HVAC equipment is used to provide whole-house ventilation, the air handler shall be powered by an electronically commutated motor.))

R403.6.2 Testing. Mechanical ventilation systems shall be tested and verified to provide the minimum ventilation flow rates required by Section R403.6. Testing shall be performed according to the ventilation equipment manufacturer's instructions, or by using a flow hood or box, flow grid, or other airflow measuring device at the mechanical ventilation fan's inlet terminals or grilles, outlet terminals or grilles, or in the connected ventilation ducts. Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official.

EXCEPTION:

Kitchen range hoods that are ducted to the outside with 6-inch (152 mm) or larger duct and not more than one 90-degree (1.57 rad) elbow or equivalent in the duct run.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-40351Table R403.6.1—Mechanical ventilation system fan efficacy.

TABLE R403.6.1

WHOLE HOUSE MECHANICAL VENTILATION SYSTEM FAN EFFICACYa

((Fan Location	Air Flow Rate Minimum (cfm)	Minimum Efficacy (cfm/watt)	Air Flow Rate Maximum (cfm)
HRV or ERV	Any	1.2 cfm/watt	Any
Range hoods	Any	2.8	Any
In-line fan	Any	2.8	Any
Bathroom, utility room	10	1.4	< 90
Bathroom, utility room	90	2.8	Any))

System Type	Air Flow Rate (cfm)	Minimum Efficacy (cfm/watt)
HRV, ERV or balanced	Any	1.2
Range hoods	Any	2.8
In-line supply or exhaust fan	Any	3.8
Other exhaust fan	<90	2.8
Other exhaust fan	≥90	3.5

For SI: 1 cfm = 28.3 L/min.
a. ((When tested in accordance with HVI Standard 916.))Design outdoor or exhausted airflow rates/watt of fan used.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-40360Section R403.7—Equipment sizing.

R403.7 Equipment sizing and efficiency rating. Heating and cooling equipment shall be sized in accordance with ACCA Manual S based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies. The output capacity of heating and cooling equipment shall not be greater than that of the smallest available equipment size that exceeds the loads calculated, including allowable oversizing limits. Equipment shall meet the minimum federal efficiency standards as referenced in Tables C403.3.2(1), C403.3.2(2), C403.3.2(3), C403.3.2(4), C403.3.2(5), C403.3.2(6), C403.3.2(7), C403.3.2(8) and C403.3.2(9) and tested and rated in accordance with the applicable test procedure.

((R403.7.1 Electric resistance zone heated units. All detached one- and two-family dwellings and multiple single-family dwellings (townhouses) up to three stories in height above grade plane using electric zonal heating as the primary heat source shall install an inverter-driven ductless mini-split heat pump in the largest zone in the dwelling. Building permit drawings shall specify the heating equipment type and location of the heating system.

EXCEPTION:

Total installed heating capacity of 2 kW per dwelling unit or less.))

R403.7.1 Gas fireplace efficiency. All vented gas fireplace heaters rated to ANSI Z21.88 shall be listed and labeled with a fireplace efficiency (FE) rating of 50 percent or greater in accordance with CSA P.4.1. Vented gas fireplaces (decorative appliances) certified to ANSI Z21.50 shall be listed and labeled, including their FE ratings, in accordance with CSA P.4.1.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40390Section R403.10—Pool and spa energy consumption.

R403.10 ((Pool and permanent spa))Energy consumption of pools and spas.The energy consumption of pools and permanent spas shall ((comply with))be controlled by the requirements in Sections R403.10.1 through R403.10.4.2.

R403.10.1 Heaters. The electric power to heaters shall be controlled by ((a readily accessible))an on-off switch that is an integral part of the heater mounted on the exterior of the heater in a location with ready access, or external to and within 3 feet (914 mm) of the heater. Operation of such switch shall not change the settings of the heater thermostat. Such switches shall be in addition to a circuit breaker for the power to the heater.

R403.10.2 Time switches. Time switches or other control method that can automatically turn off and on heaters and pump motors according to a preset schedule shall be installed for heaters and pump motors. Heaters and pump motors that have built in time switches shall be deemed in compliance with this requirement.

EXCEPTIONS:	1. Where public health standards require 24-hour pump operation.
	2. Pumps that operate solar- and waste-heat-recovery pool heating systems.

R403.10.3 Covers. Outdoor heated pools and outdoor permanent spas shall be provided with a vapor-retardant cover, or other approved vapor retardant means.

EXCEPTION:

Where more than 75 percent of the energy for heating, computed over an operating season of not ((less))fewer than three calendar months, is from a heat pump or on-site renewable energy system, covers or other vapor-retardant means shall not be required.

R403.10.4 Residential pool pumps. Pool pump motors may not be split-phase or capacitor start-induction run type.

R403.10.4.1 Two-speed capability.

1. Pump motors: Pool pump motors with a capacity of 1 hp or more shall have the capability of operating at two or more speeds with low speed having a rotation rate that is no more than one-half of the motor's maximum rotation rate.

2. Pump controls: Pool pump motor controls shall have the capability of operating the pool pump with at least two speeds. The default circulation speed shall be the lowest speed, with a high speed override capability being for a temporary period not to exceed one normal cycle.

R403.10.4.2 Pump operation. Circulating water systems shall be controlled so that the circulation pump(s) can be conveniently turned off, automatically or manually, when the water system is not in operation.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40391Section R403.10—Other pools and spas.

R403.11 Portable spas. The energy consumption of electric-powered portable spas shall be controlled by the requirements of APSP-14.

R403.12 Residential pools and permanent residential spas.((Residential swimming pools and permanent residential spas that are accessory to detached one- and two-family dwellings and townhouses three stories or less in height above grade plane and that are available only to the household and its guests))The energy consumption of residential swimming pools and permanent residential spas shall be controlled in accordance with the requirements of APSP-15.

NEW SECTION

WAC 51-11R-40392Section R403.13—Heat pump space heating.

R403.13 Heat pump space heating. Space heating shall be provided by a heat pump system.

EXEMPTIONS:	1. Detached one- and two-family dwellings and multiple-single family dwellings (townhouses up to three stories in height above grade having an installed HVAC heating capacity no greater than 1.5 watts of electric resistance heating per square foot of dwelling unit conditioned floor area, or up to 500 watts, whichever is greater.
	2. Group R-2 dwelling or sleeping units having an installed HVAC heating capacity no greater than 750 watts in Climate Zone 4, and 1,000 watts in Climate Zone 5, in any separate habitable room with exterior fenestration are permitted to be heated using electric resistance appliances. Four buildings in location with exterior design conditions below 4°F (-15.6°C), an additional 250 watts above that allowed for Climate Zone 5 is permitted.
	2.1. A room within a dwelling or sleeping unit that has two primary walls facing different cardinal directions, each with exterior fenestration, is permitted to have an installed HVAC heating capacity no greater than 1,000 watts in Climate Zone 4, and 1,300 watts in Climate Zone 5. Bay windows and other minor offsets are not considered primary walls. For buildings in location with exterior design conditions below 4°F (-15.6°C), an additional 250 watts above that allowed for Climate Zone 5 is permitted.
	3. Resistance heating elements integrated into heat pump equipment.
	4. Solar thermal systems.
	5. Waste heat, radiant heat exchanger, and energy recovery systems.
	6. Supplementary heat in accordance with Section R403.1.2.
	7. Where there is no electric utility service available at the building site.
	8. Heating systems that rely primarily on biomass are allowed in Climate Zone 5.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40410Section R404.1—Lighting equipment.

R404.1 Lighting equipment.((Not less than 90 percent of lamps in))All permanently installed lighting fixtures, excluding kitchen appliance lighting fixtures, shall ((be))contain onlyhigh-efficacy((lamps))lighting sources.

R404.1.1 Exterior lighting. Connected exterior lighting for residential buildings shall comply with Section C405.5.

EXCEPTION:

Solar-powered lamps not connected to any electrical service.

((R404.1.1))R404.1.2 Fuel gas lighting equipment. Fuel gas lighting systems shall not have continuously burning pilot lights.

R404.2 Interior lighting controls. Permanently installed interior lighting fixtures shall be controlled with either a dimmer, an occupant sensor control, or other control that is installed or built into the fixture.

EXCEPTION:	Lighting controls shall not be required for the following:
	1. Bathrooms;
	2. Hallways;
	3. Lighting designed for safety or security.

R404.3 Exterior lighting controls. Where the total permanently installed exterior lighting power is greater than 30 watts, the permanently installed exterior lighting shall comply with the following:

1. Lighting shall be controlled by a manual on and off switch which permits automatic shut-off actions.

EXCEPTION:

Lighting serving multiple dwelling units.

2. Lighting shall be automatically shut off when daylight is present and satisfies the lighting needs.

3. Controls that override automatic shut-off actions shall not be allowed unless the override automatically returns automatic control to its normal operation within 24 hours.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-40500Section R405—((Simulated performance alternative (Performance)))Total building performance.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40510Section R405.1—Scope.

R405.1 Scope. This section establishes criteria for compliance using ((simulated energy))total building performance analysis. Such analysis shall include heating, cooling, mechanical ventilation, and service water heating energy only.

AMENDATORY SECTION(Amending WSR 22-10-094, filed 5/3/22, effective 6/3/22)

WAC 51-11R-40520Section R405.2—((Mandatory requirements))Performance based compliance.

R405.2 ((Mandatory requirements))Performance based compliance. Compliance ((with this section requires compliance with those sections shown in Table R405.2. All supply and return ducts not completely inside the building thermal envelope shall be insulated to a minimum of R-8))based on total building performance requires the following:

1. The requirements of the sections indicated within Table R405.2(1).

2. For structures less than 1,500 square feet of conditioned floor area, the annual carbon emissions shall be less than or equal to 64 percent of the annual carbon emissions of the standard reference design.

3. For structures 1,500 to 5,000 square feet of conditioned floor area, the annual carbon emissions shall be no more than 47 percent of the standard reference design.

4. For structures over 5,000 square feet of conditioned floor area, the annual carbon emissions shall be no more than 41 percent of the standard reference design.

5. For structures serving Group R-2 occupancies, the annual carbon emissions shall be less than or equal to 61 percent of the annual energy consumption of the standard reference design. See Section R401.1 and residential building in Section R202 for Group R-2 scope.

Carbon emissions for both the standard reference design and the proposed design shall be calculated using Table R405.2(2). Energy use derived from simulation analysis shall be expressed in pounds of carbon per square foot of conditioned floor area.

TABLE R405.2(1)

MANDATORY COMPLIANCE MEASURES FOR ((SIMULATED PERFORMANCE ALTERNATIVE))TOTAL BUILDING PERFORMANCE

Sectiona	Title	Comments
General
R401.3	Certificate
Envelope
R402.1.1	Vapor retarder
R402.2.3	Eave baffle
R402.2.4.1	Access hatches and doors
R402.2.10.1	Crawlspace wall insulation installations
R402.4	Air leakage
R402.5	Maximum fenestration U-factor
Systems
R403.1	Controls
((R403.1.2	Heat pump supplemental heat
R403.3.2	Sealing
R403.3.1	Insulation
R403.3.3	Duct testing
R403.3.4	Duct leakage
R403.3.5	Building cavities))
R403.3	Ducts	Except for R403.3.2 and R403.3.3
R403.4	Mechanical system piping insulation
R403.5.1	Heated water circulation and temperature maintenance system
R403.5.3	Drain water heat recovery units
R403.5.7	Heat pump water heating
R403.6	Mechanical ventilation
R403.7	Equipment sizing and efficiency rating
R403.8	Systems serving multiple dwelling units
R403.9	Snow melt system controls
R403.10	((Pool and permanent spa energy consumption)) Energy consumption of pools and spas
R403.11	Portable spas
R403.12	Residential pools and permanent residential spas
R403.13	Heat pump space heating
Electrical Power and Lighting
R404.1	Lighting equipment
((R404.1.1	Lighting equipment))
R404.2	((Electric readiness)) Interior lighting controls
((Other Requirements
R406	Additional energy efficiency requirements))

a	Reference to a code section includes all the relative subsections except as indicated in the table.

TABLE R405.2(2)

CARBON EMISSIONS FACTORS

Type	CO2e (lb/unit)	Unit
Electricity	0.44	kWh
Natural gas	11.7	Therm
Oil	19.2	Gallon
Propane	10.5	Gallon
Othera	195.00	mmBtu
On-site renewable energy	0.00

a	District energy systems may use alternative emission factors supported by calculations approved by the code official.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-40530Section R405.3—((Performance-based compliance))Documentation.

((R405.3 Performance-based compliance. Compliance based on simulated energy performance requires that a proposed residence (proposed design) be shown to have an annual energy consumption based on carbon emissions of the fuels and energy use in the proposed building. Carbon emissions for both the standard reference design and the proposed design shall be calculated using Table R405.3. Energy use derived from simulation analysis shall be expressed in pounds of carbon per square foot of conditioned floor area as follows:

1. For structures less than 1,500 square feet of conditioned floor area, the annual carbon emissions shall be less than or equal to 73 percent of the annual carbon emissions of the standard reference design.

2. For structures 1,500 to 5,000 square feet of conditioned floor area, the annual carbon emissions shall be no more than 56 percent of the standard reference design.

3. For structures over 5,000 square feet of conditioned floor area, the annual carbon emissions shall be no more than 50 percent of the standard reference design.

4. For structures serving Group R-2 occupancies, the annual carbon emissions shall be less than or equal to 70 percent of the annual energy consumption of the standard reference design.

TABLE R405.3

CARBON EMISSIONS FACTORS

Type	CO2e (lb/unit)	Unit
Electricity	0.80	kWh
Natural gas	11.7	Therm
Oil	19.2	Gallon
Propane	10.5	Gallon
Othera	195.00	mmBtu
On-site renewable energy	0.00

a	District energy systems may use alternative emission factors supported by calculations approved by the code official.))

R405.3 Documentation. Documentation of the software used for the performance design and the parameters for the building shall be in accordance with Sections R405.3.1 through R405.3.3.

R405.3.1 Compliance software tools. Documentation verifying that the methods and accuracy of the compliance software tools conform to the provisions of this section shall be provided to the code official.

R405.3.2 Compliance report. Compliance software tools shall generate a report that documents that the proposed design complies with Section R405.2.

A compliance report on the proposed design shall be submitted with the application for the building permit. Upon completion of the building, a confirmed compliance report based upon the confirmed condition of the building shall be submitted to the code official before a certificate of occupancy is issued.

Compliance reports shall include information in accordance with Sections R405.3.2.1 and R405.3.2.2.

R405.3.2.1 Compliance report for permit application. A compliance report submitted with the application for building permit shall include all of the following:

1. Building street address, or other building site identification.

2. The name, organization, and contact information of the individual performing the analysis and generating the compliance report.

3. The name and version of the compliance software tool.

4. Documentation of all inputs entered into the software used to produce the results for the reference design and/or the rated home.

5. A certificate indicating that the proposed design complied with Section R405.2. The certificate shall document the building components' energy specifications that are included in the calculation including: Component-level insulation R-values or U-factors; duct system and building envelope air leakage testing assumptions; and the type and rated efficiencies of proposed heating, cooling, mechanical ventilation, and service water-heating equipment to be installed. If on-site renewable energy systems will be installed, the certificate shall report the type and production size of the proposed system. Additional documentation reporting estimated annual energy production shall be provided.

6. When a site-specific report is not generated, the proposed design shall be based on the worst-case orientation and configuration of the rated home.

R405.3.2.2 Compliance report for certificate of occupancy. A compliance report submitted for obtaining the certificate of occupancy shall include all of the following:

1. Building street address, or other building site identification.

2. Declaration of the total building performance path on the title page of the energy report and the title page of the building plans.

3. A statement bearing the name of the individual performing the analysis and generating the report, along with their organization and contact information, indicating that the as-build building complies with Section R405.2.

4. The name and version of the compliance software tool.

5. A site-specific energy analysis report that is in compliance with Section R405.2.

6. A final confirmed certificate indicating compliance based on inspection, and a statement indicating that the confirmed rated design of the built home complies with Section R405.2. The certificate shall report the energy features that were confirmed to be in the home, including component level insulation R-values or U-factors; results from any required duct system and building envelope air leakage testing; and the type and rated efficiencies of the heating, cooling, mechanical ventilation, and service water-heating equipment installed.

7. Where on-site renewable energy systems have been installed, the certificate shall report the type and production size of the installed system. Additional documentation reporting estimated annual energy production shall be provided.

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-40540Section R405.4—((Documentation))Calculation procedure.

((R405.4 Documentation. Documentation of the software used for the performance design and the parameters for the building shall be in accordance with Sections R405.4.1 through R405.4.3.

R405.4.1 Compliance software tools. Documentation verifying that the methods and accuracy of the compliance software tools conform to the provisions of this section shall be provided to the code official.

R405.4.2 Compliance report. Compliance software tools shall generate a report that documents that the proposed design complies with Section R405.3.

A compliance report on the proposed design shall be submitted with the application for the building permit. Upon completion of the building, a compliance report based upon the as-built condition of the building shall be submitted to the code official before a certificate of occupancy is issued. Batch sampling of buildings to determine energy code compliance for all buildings in the batch shall be prohibited.

Compliance reports shall include information in accordance with Sections R405.4.2.1 and R405.4.2.2. Where the proposed design of a building could be built on different sites where the cardinal orientation of the building on each site is different, compliance of the proposed design for the purposes of the application for the building permit shall be based upon the worst-case orientation, worst-case configuration, worst-case building air leakage and worst-case duct leakage. Such worst-case parameters shall be used as inputs to the compliance software for energy analysis.

R405.4.2.1 Compliance report for permit application. A compliance report submitted with the application for building permit shall include all of the following:

1. Building street address, or other building site identification.

2. A statement indicating that the proposed design complies with Section R405.3.

3. An inspection checklist documenting the building component characteristics of the proposed design as indicated in Table R405.5.2(1). The inspection checklist shall show results for both the standard reference design and the proposed design with all user inputs to the compliance software to generate the results.

4. A site-specific energy analysis report that is in compliance with Section R405.3.

5. Name of the individual performing the analysis and generating the report.

6. Name and version of the compliance software tool.

R405.4.2.2 Compliance report for certificate of occupancy. A compliance report submitted for obtaining the certificate of occupancy shall include all of the following:

1. Building street address, or other building site identification.

2. A statement indicating that the as-built building complies with Section R405.3.

3. A certificate indicating that the building passes the performance matrix for code compliance and the energy saving features of the building.

4. A site-specific energy analysis report that is in compliance with Section R405.3.

5. Name of the individual performing the analysis and generating the report.

6. Name and version of the compliance software tool.

R405.4.3 Additional documentation. The code official shall be permitted to require the following documents:

1. Documentation of the building component characteristics of the standard reference design.

2. A certification signed by the builder providing the building component characteristics of the proposed design as given in Table R405.5.2(1).

3. Documentation of the actual values used in the software calculations for the proposed design.))

R405.4 Calculation procedure. Calculations of the performance design shall be in accordance with Sections R405.4.1 and R405.4.2.

R405.4.1 General. Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.

R405.4.2 Residence specifications. The standard reference design and proposed design shall be configured and analyzed as specified by Table R405.4.2(1). Table R405.4.2(1) shall include by reference all notes contained in Table R402.1.3.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-40550((Section R405.5—Calculation procedure.))Reserved.

((R405.5 Calculation procedure. Calculations of the performance design shall be in accordance with Sections R405.5.1 and R405.5.2.

R405.5.1 General. Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.

R405.5.2 Residence specifications. The standard reference design and proposed design shall be configured and analyzed as specified by Table R405.5.2(1). Table R405.5.2(1) shall include by reference all notes contained in Table R402.1.1.))

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-40551Table ((R405.5.2(1)))R405.4.2(1)—Specifications for the standard reference and proposed designs.

TABLE ((R405.5.2(1)))R402.4.2(1)

SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS

BUILDING COMPONENT	STANDARD REFERENCE DESIGN	PROPOSED DESIGN
Above-grade walls	Type: Mass wall if proposed wall is mass; otherwise wood frame. Gross area: Same as proposed U-factor: From Table ((R402.1.3))R402.1.2 Solar absorptance = 0.75 Emittance = 0.90	As proposed As proposed As proposed As proposed As proposed
Below-grade walls	Type: Same as proposed Gross area: Same as proposed U-factor: From Table ((R402.1.3))R402.1.2, with insulation layer on interior side of walls.	As proposed As proposed As proposed
Above-grade floors	Type: Wood frame Gross area: Same as proposed U-factor: From Table ((R402.1.3))R402.1.2	As proposed As proposed As proposed
Ceilings	Type: Wood frame Gross area: Same as proposed U-factor: From Table ((R402.1.3))R402.1.2	As proposed As proposed As proposed
Roofs	Type: Composition shingle on wood sheathing Gross area: Same as proposed Solar absorptance = 0.75 Emittance = 0.90	As proposed As proposed As proposed As proposed
Attics	Type: Vented with aperture = 1 ft2 per 300 ft2 ceiling area	As proposed
Foundations	Type: Same as proposed foundation wall area above and below-grade Soil characteristics: Same as proposed.	As proposed As proposed
Opaque doors	Area: 40 ft2 Orientation: North U-factor: Same as fenestration from Table ((R402.1.3))R402.1.2.	As proposed As proposed As proposed
Vertical fenestration other than opaque doorsa	Total areah = (a) The proposed glazing area; where proposed glazing area is less than 15% of the conditioned floor area. (b) 15% of the conditioned floor area; where the proposed glazing area is 15% or more of the conditioned floor area.	As proposed
	Orientation: Equally distributed to four cardinal compass orientations (N, E, S & W).	As proposed
	U-factor: From Table ((R402.1.3))R402.1.2	As proposed
	SHGC: From Table R402.1.1 except that for climates with no requirement (NR) SHGC = 0.40 shall be used.	As proposed
	Interior shade fraction: 0.92 - (0.21 × SHGC for the standard reference design) External shading: None	0.92 - (0.21 × SHGC as proposed) As proposed
Skylights	None	As proposed
Air exchange rate	Air leakage rate of 5 air changes per hour at a pressure of 0.2 inches w.g. (50 Pa). The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 × CFA +7.5 × (Nbr + 1) where: CFA = conditioned floor area Nbr = number of bedrooms - The mechanical ventilation system type shall be the same as in the proposed design. Energy recovery shall not be assumed for mechanical ventilation.	As proposeda. The mechanical ventilation rateb shall be in addition to the air leakage rate and shall be as proposed.
Mechanical ventilation	None, except where mechanical ventilation is specified by the proposed design, in which case: Annual vent fan energy use: kWh/yr = (1ef) × (0.0876 × CFA + 65.7 × (Nbr + 1) where: ef = the minimum ((exhaust)) fan efficacy from Table R403.6.1 corresponding to the system type at a flow rate of 0.01 × CFA + 7.5 × (Nbr + 1) CFA = conditioned floor area Nbr = number of bedrooms	As proposed
Internal gains	IGain = 17,900 + 23.8 × CFA + 4104 × Nbr (Btu/day per dwelling unit)	Same as standard reference design
Internal mass	An internal mass for furniture and contents of 8 pounds per square foot of floor area.	Same as standard reference design, plus any additional mass specifically designed as a thermal storage elementc but not integral to the building envelope or structure.
Structural mass	For masonry floor slabs, 80% of floor area covered by R-2 carpet and pad, and 20% of floor directly exposed to room air.	As proposed
	For masonry basement walls, as proposed, but with insulation required by Table ((R402.1.3))R402.1.2 located on the interior side of the walls.	As proposed
	For other walls, for ceilings, floors, and interior walls, wood frame construction.	As proposed
Heating systemsd, e	((Where the proposed design utilizes electric heating without a heat pump))The standard reference design shall be an air source heat pump meeting the requirements of Section C403 of the WSEC—Commercial Provisions. ((For all other systems, the same system type as proposed, and the same system efficiency required by prevailing minimum federal standard.)) Capacity: Sized in accordance with Section R403.6	As proposed
Cooling systemsd, f	Same system type as proposed. Same system efficiency as required by prevailing minimum federal standard. Capacity: Sized in accordance with Section R403.6.	As proposed
Service water heatingd, e, f, g	((Same system type as proposed. Same system efficiency as required by prevailing minimum federal standard. Use: Same as proposed design)) The standard reference design shall be a heat pump water heating meeting the standards for Tier 1 of NEEA's Advanced Water Heating Specifications. Use, in units of gal/day = 25.5 + (8.5 x Nbr) Where Nbr = number of bedrooms	As proposed ((gal/day = 30 + (10 × Nbr))) Use, in units of gal/day = 25.5 + (8.5 x Nbr) x (1 - HWDS) Where: Nbr= number of bedrooms HWDS = factor for the compactness of the hot water distribution system
Thermal distribution systems	Duct insulation: From Section R403.3.3. Duct location: Same as proposed design. A thermal distribution system efficiency (DSE) of 0.93 shall be applied to both the heating and cooling system efficiencies for all systems. Exception: For nonducted heating and cooling systems that do not have a fan, the standard reference design distribution system efficiency ( DSE) shall be 1.	Duct insulation: As proposed. Duct location: As proposed. As specified in Table R405.5.2(2).
Thermostat	Type: Manual, cooling temperature setpoint = 75°F; Heating temperature setpoint = 72°F	Same as standard reference

For SI:

1 square foot = 0.93 m2, 1 British thermal unit = 1055 J, 1 pound per square foot = 4.88 kg/m2, 1 gallon (U.S.) = 3.785 L, °C = (°F-3)/1.8, 1 degree = 0.79 rad

a	Where required by the code official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent, shall be used to determine the energy loads resulting from infiltration.
b	The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.24 and the "Whole-house Ventilation" provisions of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.
c	Thermal storage element shall mean a component not part of the floors, walls or ceilings that is part of a passive solar system, and that provides thermal storage such as enclosed water columns, rock beds, or phase-change containers. A thermal storage element must be in the same room as fenestration that faces within 15 degrees (0.26 rad) of true south, or must be connected to such a room with pipes or ducts that allow the element to be actively charged.
d	For a proposed design with multiple heating, cooling or water heating systems using different fuel types, the applicable standard reference design system capacities and fuel types shall be weighted in accordance with their respective loads as calculated by accepted engineering practice for each equipment and fuel type present.
e	For a proposed design without a proposed heating system, a heating system with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and proposed design.
f	For a proposed design home without a proposed cooling system, an electric air conditioner with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and the proposed design.
g	For a proposed design with a nonstorage-type water heater, a 40-gallon storage-type water heater with the prevailing federal minimum energy factor for the same fuel as the predominant heating fuel type shall be assumed. For the case of a proposed design without a proposed water heater, a 40-gallon storage-type water heater with the prevailing federal minimum efficiency for the same fuel as the predominant heating fuel type shall be assumed for both the proposed design and standard reference design.
h	For residences with conditioned basements, R-2 and R-4 residences and townhouses, the following formula shall be used to determine fenestration area:

AF = As x FA x F
Where:
AF	=	Total fenestration area.
As	=	Standard reference design total fenestration area.
FA	=	(Above-grade thermal boundary gross wall area)/(above-grade boundary wall area + 0.5 x below-grade boundary wall area).
F	=	(Above-grade thermal boundary wall area)/(above-grade thermal boundary wall area + common wall area) or 0.56, whichever is greater.
and where:
Thermal boundary wall is any wall that separates conditioned space from unconditioned space or ambient conditions.
Above-grade thermal boundary wall is any thermal boundary wall component not in contact with soil.
Below-grade boundary wall is any thermal boundary wall in soil contact.
Common wall area is the area of walls shared with an adjoining dwelling unit.
L and CFA are in the same units.

i	The factor for the compactness of the hot water distribution system is the ratio of the area of the rectangle that bounds the source of hot water and the fixtures that it serves (the "hot water rectangle") divided by the floor area of the dwelling.
	1. Sources of hot water include water heaters, or in multifamily buildings with central water heating systems, circulation loops, or electric heat traced pipes.
	2. The hot water rectangle shall include the source of hot water and the points of termination of all hot water fixture supply piping.
	3. The hot water rectangle shall be shown on the floor plans and the area shall be computed to the nearest square foot.
	4. Where there is more than one water heater and each water heater serves different plumbing fixtures and appliances, it is permissible to establish a separate hot water rectangle for each hot water distribution system and add the area of these rectangles together to determine the compactness ratio.
	5. The basement or attic shall be counted as a story when it contains the water heater.
	6. Compliance shall be demonstrated by providing a drawing on the plans that shows the hot water distribution system rectangle(s), comparing the area of the rectangle(s) to the area of the dwelling and identifying the appropriate compactness ratio and HWDS factor.

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-40552Table ((R405.5.2(2)))R405.4.2(2)—Default distribution system efficiencies for proposed designs.

TABLE ((R405.5.2(2)))R402.4.2(2)

DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNSa

DISTRIBUTION SYSTEM CONFIGURATION AND CONDITION	DISTRIBUTION SYSTEM EFFICIENCY
Distribution system components located in unconditioned space	0.88
Distribution systems entirely located in conditioned spaceb	0.93
Zonal systemsc	1.00

For SI:	1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093m2, 1 pound per square inch = 6895 Pa, 1 inch water gauge = 1250 Pa.
	a Values given by this table are for distribution systems, which must still meet all prescriptive requirements for duct and pipe system insulation and leakage.
	b Entire system in conditioned space shall mean that no component of the distribution system, including the air-handler unit, is located outside of the conditioned space. All components must be located on the interior side of the thermal envelope (inside the insulation) and also inside of the air barrier. Refrigerant compressors and piping are allowed to be located outside.
	c Zonal systems are systems where the heat source is located within each room. Systems shall be allowed to have forced airflow across a coil but shall not have any ducted airflow external to the manufacturer's air-handler enclosure. Hydronic systems do not qualify.

AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)

WAC 51-11R-40560Section ((R405.6))R405.5—Calculation software tools.

((R405.6))R405.5 Calculation software tools. Calculation software, where used, shall be in accordance with Sections ((R405.6.1))R405.5.1 through ((R405.6.3))R405.5.3.

((R405.6.1))R405.5.1 Minimum capabilities. Calculation procedures used to comply with this section shall be software tools capable of calculating the annual energy consumption of all building elements that differ between the standard reference design and the proposed design and shall include the following capabilities:

1. Calculation of whole-building (as a single zone) sizing for the heating and cooling equipment in the standard reference design residence in accordance with Section R403.6.

2. Calculations that account for the effects of indoor and outdoor temperatures and part-load ratios on the performance of heating, ventilating and air-conditioning equipment based on climate and equipment sizing.

3. Printed code official inspection checklist listing each of the proposed design component characteristics from Table R405.5.2(1) determined by the analysis to provide compliance, along with their respective performance ratings (e.g., R-value, U-factor, SHGC, HSPF, AFUE, SEER, EF, etc.).

((R405.6.2))R405.5.2 Specific approval. Performance analysis tools meeting the applicable sections of Section R405 shall be permitted to be approved. Tools are permitted to be approved based on meeting a specified threshold for a jurisdiction. The code official shall be permitted to approve tools for a specified application or limited scope.

((R405.6.3))R405.5.3 Input values. When calculations require input values not specified by Sections R402, R403, R404 and R405, those input values shall be taken from an approved source.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40610Section R406.1—Scope.

R406.1 Scope. This section establishes additional energy efficiency requirements for all new construction covered by this code, including additions subject to Section R502 and change of occupancy or use subject to Section R505 unless specifically exempted in Section R406. Credits from both Sections R406.2 and R406.3 are required.

R406.2 Carbon emission equalization. This section establishes a base equalization between fuels used to define the equivalent carbon emissions of the options specified. The permit shall define the base fuel selection to be used and the points specified in Table R406.2 shall be used to modify the requirements in Section R406.3. ((The sum of credits from Tables R406.2 and R406.3 shall meet the requirements of Section R406.3.))

TABLE R406.2

FUEL NORMALIZATION CREDITS

TABLE R406.2 OPTION 1 (TAG Recommendation based on initial proposal to achieve targeted energy savings for the cycle)

System Type	Description of Primary Heating Source	Credits
System Type	Description of Primary Heating Source	All Other	Group R-2a
((1	Combustion heating equipment meeting minimum federal efficiency standards for the equipment listed in Table C403.3.2(4) or C403.3.2(5)	0	0
2	For an initial heating system using a heat pump that meets federal standards for the equipment listed in Table C403.3.2(1)C or C403.3.2(2) or Air to water heat pump units that are configured to provide both heating and cooling and are rated in accordance with AHRI 550/590	1.0	1.0
3	For heating system based on electric resistance only (either forced air or Zonal)	-1.0	-1.0
4	For heating system based on electric resistance with a ductless mini-split heat pump system in accordance with Section R403.7.1 including the exception	0.5	N/A
5	All other heating systems	-1	-0.5))
1	For combustion heating system using equipment meeting minimum federal efficiency standards for the equipment listed in Table C403.3.2(4) or C403.3.2(5)	0	0
2	For a primary heating system using a heat pump that meets federal standards for the equipment listed in Table C403.3.2(2) and secondary heating provided by a combustion furnace meeting minimum standards listed in Table C403.3.2(4)b	1.5	0
3	For heating system based on electric resistance only (either forced air or zonal)	0.5	-0.5
4c	For an initial heating system using a heat pump that meets federal standards for the equipment listed in Table C403.3.2(1)C or C403.3.2(2) or Air to water heat pump units that are configured to provide both heating and cooling and are rated in accordance with AHRI 550/590	3.0	2.0
5	For heating system based on electric resistance with: 1. Inverter-driven ductless mini-split heat pump system installed in the largest zone in the dwelling or 2. With 2 kW or less total installed heating capacity per dwelling	2.0	0

a	See Section R401.1 and residential building in Section R202 for Group R-2 scope.
b	The gas back-up furnace will operate as fan-only when the heat pump is operating. The heat pump shall operate at all temperatures above 38°F (3.3°C) (or lower). Below that "changeover" temperature, the heat pump would not operate to provide space heating. The gas furnace provides heating below 38°F (3.3°C) (or lower).
c	Additional points for this HVAC system are included in Table R406.3.

TABLE R406.2 OPTION 2 (Post-TAG modifications to account for energy savings of other proposals to achieve the targeted energy reduction for the cycle)

System Type	Description of Primary Heating Source	Credits
System Type	Description of Primary Heating Source	All Other	Group R-2a
((1	Combustion heating equipment meeting minimum federal efficiency standards for the equipment listed in Table C403.3.2(4) or C403.3.2(5)	0	0
2	For an initial heating system using a heat pump that meets federal standards for the equipment listed in Table C403.3.2(1)C or C403.3.2(2) or Air to water heat pump units that are configured to provide both heating and cooling and are rated in accordance with AHRI 550/590	1.0	1.0
3	For heating system based on electric resistance only (either forced air or Zonal)	-1.0	-1.0
4	For heating system based on electric resistance with a ductless mini-split heat pump system in accordance with Section R403.7.1 including the exception	0.5	N/A
5	All other heating systems	-1	-0.5))
1	For combustion heating system using equipment meeting minimum federal efficiency standards for the equipment listed in Table C403.3.2(4) or C403.3.2(5)	0	0
2	For an initial heating system using a heat pump that meets federal standards for the equipment listed in Table C403.3.2(2) and secondary heating provided by a combustion furnace meeting minimum standards listed in Table C403.3.2(4)b	1.5	2.0
3	For heating system based on electric resistance only (either forced air or zonal)	0.5	0
4c	For an initial heating system using a heat pump that meets federal standards for the equipment listed in Table C403.3.2(1)C or C403.3.2(2) or Air to water heat pump units that are configured to provide both heating and cooling and are rated in accordance with AHRI 550/590	-1.0	-0.5
5	For heating system based on electric resistance with: 1. Inverter-driven ductless mini-split heat pump system installed in the largest zone in the dwelling or 2. With 2 kW or less total installed heating capacity per dwelling	-3.0	0

a	See Section R401.1 and residential building in Section R202 for Group R-2 scope.
b	The gas back-up furnace will operate as fan-only when the heat pump is operating. The heat pump shall operate at all temperatures above 38°F (3.3°C) (or lower). Below that "changeover" temperature, the heat pump would not operate to provide space heating. The gas furnace provides heating below 38°F (3.3°C) (or lower).
c	Additional points for this HVAC system are included in Table R406.3.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-40620Section R406.3—Additional energy efficiency requirements.

R406.3 Additional energy efficiency requirements. Each dwelling unit in a residential building shall comply with sufficient options from Table R406.2 and R406.3 so as to achieve the following minimum number of credits:

OPTION 1 (TAG Recommendation based on initial proposal to achieve targeted energy savings for the cycle)

1.	Small Dwelling Unit:	((3.0))5.0 credits
	Dwelling units less than 1500 square feet in conditioned floor area with less than 300 square feet of fenestration area. Additions to existing building that are greater than 500 square feet of heated floor area but less than 1500 square feet.
2.	Medium Dwelling Unit:	((6.0))8.0 credits
	All dwelling units that are not included in #1, #3, or #4.
3.	Large Dwelling Unit:	((7.0))9.0 credits
	Dwelling units exceeding 5000 square feet of conditioned floor area.
4.	Dwelling units serving Group R-2 occupancies. See Section R401.1 and residential building in Section R202 for Group R-2 scope.	((4.5))6.5 credits
5.	Additions((less than or equal to))150 to 500 square feet:	((1.5))2.0 credits

OPTION 2 (Post-TAG modifications to account for energy savings of other proposals to achieve the targeted energy reduction for the cycle)

1.	Small Dwelling Unit:	((3.0))2.5 credits
	Dwelling units less than 1500 square feet in conditioned floor area with less than 300 square feet of fenestration area. Additions to existing building that are greater than 500 square feet of heated floor area but less than 1500 square feet.
2.	Medium Dwelling Unit:	((6.0))5.0 credits
	All dwelling units that are not included in #1, #3, or #4.
3.	Large Dwelling Unit:	((7.0))6.0 credits
	Dwelling units exceeding 5000 square feet of conditioned floor area.
4.	Dwelling units serving Group R-2 occupancies. See Section R401.1 and residential building in Section R202 for Group R-2 scope.	4.5 credits
5.	Additions((less than or equal to))150 square feet to 500 square feet:	((1.5))2.0 credits

The drawings included with the building permit application shall identify which options have been selected and the point value of each option, regardless of whether separate mechanical, plumbing, electrical, or other permits are utilized for the project.

AMENDATORY SECTION(Amending WSR 22-10-094, filed 5/3/22, effective 6/3/22)

WAC 51-11R-40621Table R406.3—Energy credits.

TABLE 406.3

ENERGY CREDITS

((OPTION	DESCRIPTION	CREDIT(S)
((OPTION	DESCRIPTION	All Other	Group R-2
1. EFFICIENT BUILDING ENVELOPE OPTIONS Only one option from Items 1.1 through 1.7 may be selected in this category. Compliance with the conductive UA targets is demonstrated using Section R402.1.4, Total UA alternative, where [1-(Proposed UA/Target UA)] > the required %UA reduction
1.1	Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.24.	0.5	0.5
1.2	Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.20.	1.0	1.0
1.3	Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.28 Floor R-38 Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.4: Reduce the Total conductive UA by 5%.	0.5	N/A
1.4	Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.25 Wall R-21 plus R-4 ci Floor R-38 Basement wall R-21 int plus R-5 ci Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.4: Reduce the Total conductive UA by 15%.	1.0	1.0
1.5	Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.22 Ceiling and single-rafter or joist-vaulted R-49 advanced Wood frame wall R-21 int plus R-12 ci Floor R-38 Basement wall R-21 int plus R-12 ci Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.4: Reduce the Total conductive UA by 30%.	2.0	1.5
1.6	Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.18 Ceiling and single-rafter or joist-vaulted R-60 advanced Wood frame wall R-21 int plus R-16 ci Floor R-48 Basement wall R-21 int plus R-16 ci Slab on grade R-20 perimeter and under entire slab Below grade slab R-20 perimeter and under entire slab or Compliance based on Section R402.1.4: Reduce the Total conductive UA by 40%.	3.0	2.0
1.7	Advanced framing and raised heel trusses or rafters Vertical Glazing U-0.28 R-49 Advanced (U-0.020) as listed in Section A102.2.1, Ceilings below a vented attic and R-49 vaulted ceilings with full height of uncompressed insulation extending over the wall top plate at the eaves.	0.5	0.5
2. AIR LEAKAGE CONTROL AND EFFICIENT VENTILATION OPTIONS Only one option from Items 2.1 through 2.4 may be selected in this category.
2.1	Compliance based on R402.4.1.2: Reduce the tested air leakage to 3.0 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.3 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a high efficiency fan(s) (maximum 0.35 watts/cfm), not interlocked with the furnace fan (if present). Ventilation systems using a furnace including an ECM motor are allowed, provided that they are controlled to operate at low speed in ventilation only mode. To qualify to claim this credit, the building permit drawings shall specify the option being selected, the maximum tested building air leakage, and shall show the qualifying ventilation system and its control sequence of operation.	0.5	1.0
2.2	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 2.0 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.25 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.65. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	1.0	1.5
2.3	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 1.5 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.20 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.75. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	1.5	2.0
2.4	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.6 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.15 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.80. Duct installation shall comply with Section R403.3.7. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	2.0	2.5
3. HIGH EFFICIENCY HVAC EQUIPMENT OPTIONS Only one option from Items 3.1 through 3.6 may be selected in this category.
3.1a	Energy Star rated (U.S. North) Gas or propane furnace with minimum AFUE of 95% or Energy Star rated (U.S. North) Gas or propane boiler with minimum AFUE of 90%. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.0	1.0
3.2a	Air-source centrally ducted heat pump with minimum HSPF of 9.5. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.0	N/A
3.3a	Closed-loop ground source heat pump; with a minimum COP of 3.3 or Open loop water source heat pump with a maximum pumping hydraulic head of 150 feet and minimum COP of 3.6. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.5	1.0
3.4	Ductless mini-split heat pump system, zonal control: In homes where the primary space heating system is zonal electric heating, a ductless mini-split heat pump system with a minimum HSPF of 10.0 shall be installed and provide heating to the largest zone of the housing unit. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.5	2.0
3.5a	Air-source, centrally ducted heat pump with minimum HSPF of 11.0. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.5	N/A
3.6a	Ductless split system heat pumps with no electric resistance heating in the primary living areas. A ductless heat pump system with a minimum HSPF of 10 shall be sized and installed to provide heat to entire dwelling unit at the design outdoor air temperature. To qualify to claim this credit, the building permit drawings shall specify the option being selected, the heated floor area calculation, the heating equipment type(s), the minimum equipment efficiency, and total installed heat capacity (by equipment type).	2.0	3.0
4. HIGH EFFICIENCY HVAC DISTRIBUTION SYSTEM OPTIONS
4.1	All supply and return ducts located in an unconditioned attic shall be deeply buried in ceiling insulation in accordance with Section R403.3.6. For mechanical equipment located outside the conditioned space, a maximum of 10 linear feet of return duct and 5 linear feet of supply duct connections to the equipment may be outside the deeply buried insulation. All metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic. If flex ducts are used, they cannot contain splices. Duct leakage shall be limited to 3 cfm per 100 square feet of conditioned floor area. Air handler(s) shall be located within the conditioned space.	0.5	0.5
4.2	HVAC equipment and associated duct system(s) installation shall comply with the requirements of Section R403.3.7. Locating system components in conditioned crawl spaces is not permitted under this option. Electric resistance heat and ductless heat pumps are not permitted under this option. Direct combustion heating equipment with AFUE less than 80% is not permitted under this option. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and shall show the location of the heating and cooling equipment and all the ductwork.	1.0	N/A
5. EFFICIENT WATER HEATING OPTIONS Only one option from Items 5.2 through 5.6 may be selected in this category. Item 5.1 may be combined with any option.
5.1	A drain water heat recovery unit(s) shall be installed, which captures waste water heat from all and only the showers, and has a minimum efficiency of 40% if installed for equal flow or a minimum efficiency of 54% if installed for unequal flow. Such units shall be rated in accordance with CSA B55.1 or IAPMO IGC 346-2017 and be so labeled. To qualify to claim this credit, the building permit drawings shall include a plumbing diagram that specifies the drain water heat recovery units and the plumbing layout needed to install it. Labels or other documentation shall be provided that demonstrates that the unit complies with the standard.	0.5	0.5
5.2	Water heating system shall include one of the following: Energy Star rated gas or propane water heater with a minimum UEF of 0.80. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	0.5	0.5
5.3	Water heating system shall include one of the following: Energy Star rated gas or propane water heater with a minimum UEF of 0.91 or Solar water heating supplementing a minimum standard water heater. Solar water heating will provide a rated minimum savings of 85 therms or 2000 kWh based on the Solar Rating and Certification Corporation (SRCC) Annual Performance of OG-300 Certified Solar Water Heating Systems or Water heater heated by ground source heat pump meeting the requirements of Option 3.3. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency and, for solar water heating systems, the calculation of the minimum energy savings.	1.0	1.0
5.4	Water heating system shall include one of the following: Electric heat pump water heater meeting the standards for Tier I of NEEA's advanced water heating specification or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier I of NEEA's advanced water heating specification, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	1.5	2.0
5.5	Water heating system shall include one of the following: Electric heat pump water heater meeting the standards for Tier III of NEEA's advanced water heating specification or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier III of NEEA's advanced water heating specification, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	2.0	2.5
5.6	Water heating system shall include one of the following: Electric heat pump water heater with a minimum UEF of 2.9 and utilizing a split system configuration with the air-to-refrigerant heat exchanger located outdoors. Equipment shall meet Section 4, requirements for all units, of the NEEA standard Advanced Water Heating Specification with the UEF noted above or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier III of NEEA's advanced water heating specification and utilizing a split system configuration with the air-to-refrigerant heat exchanger located outdoors, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	2.5	3.0
6. RENEWABLE ELECTRIC ENERGY OPTION
6.1	For each 1200 kWh of electrical generation per housing unit provided annually by on-site wind or solar equipment a 1.0 credit shall be allowed, up to 3 credits. Generation shall be calculated as follows: For solar electric systems, the design shall be demonstrated to meet this requirement using the National Renewable Energy Laboratory calculator PVWATTs or approved alternate by the code official. Documentation noting solar access shall be included on the plans. For wind generation projects designs shall document annual power generation based on the following factors: The wind turbine power curve; average annual wind speed at the site; frequency distribution of the wind speed at the site and height of the tower. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the photovoltaic or wind turbine equipment type, provide documentation of solar and wind access, and include a calculation of the minimum annual energy power production.	1.0	1.0
7. APPLIANCE PACKAGE OPTION
7.1	All of the following appliances shall be new and installed in the dwelling unit and shall meet the following standards: Dishwasher - Energy Star rated Refrigerator (if provided) - Energy Star rated Washing machine - Energy Star rated Dryer - Energy Star rated, ventless dryer with a minimum CEF rating of 5.2. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the appliance type and provide documentation of Energy Star compliance. At the time of inspection, all appliances shall be installed and connected to utilities. Dryer ducts and exterior dryer vent caps are not permitted to be installed in the dwelling unit.	0.5	1.5))

OPTION 1 (TAG Recommendation based on initial proposal to achieve targeted energy savings for the cycle)

		CREDIT(S)
		All Other		Group R-2b
OPTION	DESCRIPTION	Table R406.2 System Type 1, 2, 3	Table R406.2 System Type 4, 5	Any
1. EFFICIENT BUILDING ENVELOPE OPTIONS Only one option from Items 1.1 through 1.6 may be selected in this category. Compliance with the conductive UA targets is demonstrated using Section R402.1.5, Total UA alternative, where [1-(Proposed UA/Target UA)] ˃; the required %UA reduction
1.1	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.24.	0.5	0.5	0.5
1.2	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.20.	1.0	1.0	1.0
1.3	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.28 Floor R-38 Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 5%.	0.5	N/A	N/A
1.4	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.24 Floor R-38 Basement wall R-21 int plus R-5 ci Ceiling and single-rafter or joist-vaulted R-60 advanced Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 15%.	1.0	0.5	1.0
1.5	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.18 Ceiling and single-rafter or joist-vaulted R-60 advanced Floor R-38 Basement wall R-21 int plus R-12 ci Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 22.5%.	1.5	1.0	1.5
1.6	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.18 Ceiling and single-rafter or joist-vaulted R-60 advanced Wood frame wall R-21 int plus R-16 ci Floor R-48 Basement wall R-21 int plus R-16 ci Slab on grade R-20 perimeter and under entire slab Below grade slab R-20 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 30%.	2.5	1.5	2.0
2. AIR LEAKAGE CONTROL AND EFFICIENT VENTILATION OPTIONS Only one option from Items 2.1 through 2.3 may be selected in this category.
2.1	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 2.0 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.25 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.65. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	1.0	0.5	1.0
2.2	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 1.5 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.20 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.75. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	1.5	1.0	1.5
2.3	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.6 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.15 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.80. Duct installation shall comply with Section R403.3.7. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	2.0	1.5	2.0
3. HIGH EFFICIENCY HVAC EQUIPMENT OPTIONS Only one option from Items 3.1 through 3.7 may be selected in this category.
3.1a	Energy Star rated (U.S. North) Gas or propane furnace with minimum AFUE of 95% or Energy Star rated (U.S. North) Gas or propane boiler with minimum AFUE of 90%. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.0	N/A	1.0
3.2a	Air-source centrally ducted heat pump with minimum HSPF of 9.5. In areas where the winter design temperature as specified in Appendix RC is 23°F or below, a cold climate heat pumpfound on the NEEP cc ASHP qualified product list shall be used. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	N/A	0.5	N/A
3.3a	Closed-loop ground source heat pump; with a minimum COP of 3.3 or Open loop water source heat pump with a maximum pumping hydraulic head of 150 feet and minimum COP of 3.6. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	N/A	1.5	1.0
3.4	Ductless mini-split heat pump system, zonal control: In homes where the primary space heating system is zonal electric heating, a ductless mini-split heat pump system with a minimum HSPF of 10.0 shall be installed and provide heating to the largest zone of the housing unit. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	N/A	1.5	2.0
3.5a	Air-source, centrally ducted heat pump with minimum HSPF of 11.0. A centrally ducted air source cold climate variable capacity heat pump (cc VHP) found on the NEEP cc VCHP qualified product list with a minimum of 10 HSPF may be used to satisfy this requirement. In areas where the winter design temperature as specified in Appendix RC is 23°F or below, an air source centrally ducted heat pump shall be a cold climate variable capacity heat pump as listed on the NEEP qualified product list. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	N/A	1.0	N/A
3.6a	Ductless split system heat pumps with no electric resistance heating in the primary living areas. A ductless heat pump system with a minimum HSPF of 10 shall be sized and installed to provide heat to entire dwelling unit at the design outdoor air temperature. Exception: In homes with total heating loads of 24,000 or less using multi-zone mini-split systems with nominal ratings of 24,000 or less, the minimum HSPF to claim this credit shall be 9 HSPF. To qualify to claim this credit, the building permit drawings shall specify the option being selected, the heated floor area calculation, the heating equipment type(s), the minimum equipment efficiency, and total installed heat capacity (by equipment type).	N/A	2.0	3.0
3.7a	Air-to-water heat pump with minimum COP of 3.2 at 47°F, rated in accordance with AHRI 550/590 by an accredited or certified testing lab. To qualify to claim this credit, the building permit drawings shall specify the option being selected, the heated floor area calculation, the heating equipment type(s), the minimum equipment efficiency, and total installed heat capacity (by equipment type).	N/A	1.0	N/A
3.8c	Connected thermostat meeting ENERGY STAR Certified Smart Thermostats/EPA ENERGY STAR specifications. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the thermostat model.	0.5	0.5	0.5
4. HIGH EFFICIENCY HVAC DISTRIBUTION SYSTEM OPTIONS
4.1	All supply and return ducts located in an unconditioned attic shall be deeply buried in ceiling insulation in accordance with Section R403.3.3. For mechanical equipment located outside the conditioned space, a maximum of 10 linear feet of return duct and 5 linear feet of supply duct connections to the equipment may be outside the deeply buried insulation. All metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic. If flex ducts are used, they cannot contain splices. Duct leakage shall be limited to 3 cfm per 100 square feet of conditioned floor area. Air handler(s) shall be located within the conditioned space.	1.0	0.5	0.5
4.2	HVAC equipment and associated duct system(s) installation shall comply with the requirements of Section R403.3.2. Electric resistance heat and ductless heat pumps are not permitted under this option. Direct combustion heating equipment with AFUE less than 80% is not permitted under this option. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and shall show the location of the heating and cooling equipment and all the ductwork.	1.5	1.0	N/A
5. EFFICIENT WATER HEATING OPTIONS Only one option from Items 5.3 through 5.6 may be selected in this category. Items 5.1 and 5.2 may be combined with any option.
5.1	A drain water heat recovery unit(s) shall be installed, which captures wastewater heat from at least two showers, including tub/shower combinations. It is acceptable, but not required, for sink water to be connected. Unit shall have a minimum efficiency of 40% if installed for equal flow or a minimum efficiency of 54% if installed for unequal flow. Such units shall be rated in accordance with CSA B55.1 or IAPMO IGC 346-2017 and be so labeled. To qualify to claim this credit, the building permit drawings shall include a plumbing diagram that specifies the drain water heat recovery units and the plumbing layout needed to install it. Labels or other documentation shall be provided that demonstrates that the unit complies with the standard.	0.5	0.5	0.5
5.2	For Compact Hot Water Distribution system credit, the volume shall store not more than 16 ounces of water between the nearest source of heated water and the termination of the fixture supply pipe where calculated using Section R403.5.2. Construction documents shall indicate the ounces of water in piping between the hot water source and the termination of the fixture supply. When the hot water source is the nearest primed plumbing loop or trunk, this must be primed with an On Demand recirculation pump and must run a dedicated ambient return line from the furthest fixture or end of loop to the water heater. To qualify for this credit, the dwelling must have a minimum of 1.5 bathrooms.	0.5	0.5	0.5
5.3	Water heating system shall include one of the following: Energy Star rated gas or propane water heater with a minimum UEF of 0.80. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	0.5	0.5	0.5
5.4	Water heating system shall include one of the following: Energy Star rated gas or propane water heater with a minimum UEF of 0.91 or Solar water heating supplementing a minimum standard water heater. Solar water heating will provide a rated minimum savings of 85 therms or 2000 kWh based on the Solar Rating and Certification Corporation (SRCC) Annual Performance of OG-300 Certified Solar Water Heating Systems or Water heater heated by ground source heat pump meeting the requirements of Option 3.3. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency and, for solar water heating systems, the calculation of the minimum energy savings.	1.0	1.0	1.0
5.5	Water heating system shall include one of the following: Electric heat pump water heater meeting the standards for Tier III of NEEA's advanced water heating specification or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier III of NEEA's advanced water heating specification, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	2.0	2.0	2.5
5.6	Water heating system shall include one of the following: Electric heat pump water heater with a minimum UEF of 2.9 and utilizing a split system configuration with the air-to-refrigerant heat exchanger located outdoors. Equipment shall meet Section 4, requirements for all units, of the NEEA standard Advanced Water Heating Specification with the UEF noted above or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier III of NEEA's advanced water heating specification and utilizing a split system configuration with the air-to-refrigerant heat exchanger located outdoors, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	2.5	2.5	3.0
6. RENEWABLE ELECTRIC ENERGY OPTION
6.1	For each 600 kWh of electrical generation per housing unit provided annually by on-site wind or solar equipment a 0.5 credit shall be allowed, up to 4.5 credits. Generation shall be calculated as follows: For solar electric systems, the design shall be demonstrated to meet this requirement using the National Renewable Energy Laboratory calculator PVWATTs or approved alternate by the code official. Documentation noting solar access shall be included on the plans. For wind generation projects designs shall document annual power generation based on the following factors: The wind turbine power curve; average annual wind speed at the site; frequency distribution of the wind speed at the site and height of the tower. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the photovoltaic or wind turbine equipment type, provide documentation of solar and wind access, and include a calculation of the minimum annual energy power production.	0.5 – 4.5	0.5 – 4.5	0.5 – 4.5
7. APPLIANCE PACKAGE OPTION
7.1	All of the following appliances shall be new and installed in the dwelling unit and shall meet the following standards: 1. Dishwasher, standard - Energy Star rated, Most Efficient 2021 or Dishwasher, compact – Energy Star rated (Version 6.0) 2. Refrigerator (if provided) - Energy Star rated (Version 5.1) 3. Washing machine (Residential) - Energy Star rated (Version 8.1) 4. Dryer - Energy Star rated, Most Efficient 2022 To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the appliance type and provide documentation of Energy Star compliance. At the time of inspection, all appliances shall be installed and connected to utilities. Dryer ducts and exterior dryer vent caps are not permitted to be installed in the dwelling unit.	0.5	0.5	1.5

a	An alternative heating source sized at a maximum of 0.5 Watts/ft2 (equivalent) of heated floor area or 500 Watts, whichever is bigger, may be installed in the dwelling unit.
b	See Section R401.1 and residential building in Section R202 for Group R-2 scope.
c	Option 3.8 can only be taken with Options 3.1 and 3.2.

OPTION 2 (Post-TAG modifications to account for energy savings of other proposals to achieve the targeted energy reduction for the cycle)

OPTION	DESCRIPTION	CREDIT(S)
OPTION	DESCRIPTION	All Other	Group R-2b
1. EFFICIENT BUILDING ENVELOPE OPTIONS Only one option from Items 1.1 through 1.4 may be selected in this category. Compliance with the conductive UA targets is demonstrated using Section R402.1.5, Total UA alternative, where [1-(Proposed UA/Target UA)] ˃; the required %UA reduction
1.1	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.22.	0.5	0.5
1.2	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.25 Floor R-38 Basement wall R-21 int plus R-5 ci Ceiling and single-rafter or joist-vaulted R-60 advanced Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 15%.	0.5	1.0
1.3	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.18 Ceiling and single-rafter or joist-vaulted R-60 advanced Floor R-38 Basement wall R-21 int plus R-12 ci Slab on grade R-10 perimeter and under entire slab Below grade slab R-10 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 22.5%.	1.0	1.5
1.4	Prescriptive compliance is based on Table R402.1.3 with the following modifications: Vertical fenestration U = 0.18 Ceiling and single-rafter or joist-vaulted R-60 advanced Wood frame wall R-21 int plus R-16 ci Floor R-48 Basement wall R-21 int plus R-16 ci Slab on grade R-20 perimeter and under entire slab Below grade slab R-20 perimeter and under entire slab or Compliance based on Section R402.1.5: Reduce the Total conductive UA by 30%.	1.5	2.0
2. AIR LEAKAGE CONTROL AND EFFICIENT VENTILATION OPTIONS Only one option from Items 2.1 through 2.3 may be selected in this category.
2.1	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 2.0 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.25 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.65. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	0.5	1.0
2.2	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 1.5 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.20 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.75. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	1.0	1.5
2.3	Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.6 air changes per hour maximum at 50 Pascals or For R-2 Occupancies, optional compliance based on Section R402.4.1.2: Reduce the tested air leakage to 0.15 cfm/ft2 maximum at 50 Pascals and All whole house ventilation requirements as determined by Section M1505.3 of the International Residential Code or Section 403.8 of the International Mechanical Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.80. Duct installation shall comply with Section R403.3.7. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.	1.5	2.0
3. HIGH EFFICIENCY HVAC EQUIPMENT OPTIONS Only one option from Items 3.1 through 3.8 may be selected in this category.
3.1a	For a System Type 1 in Table R406.2: Energy Star rated (U.S. North) gas or propane furnace with minimum AFUE of 95%. or Energy Star rated (U.S. North) gas or propane boiler with minimum AFUE of 90% To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.0	1.0
3.2a	For secondary heating system serving System Type 2 in Table R406.2: Energy Star rated (U.S. North) Gas or propane furnace with minimum AFUE of 95% or Energy Star rated (U.S. North) Gas or propane boiler with minimum AFUE of 90%. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	0.5	0.5
3.3a,d	Air-source centrally ducted heat pump with minimum HSPF of 9.5. In areas where the winter design temperature as specified in Appendix RC is 23°F or below, a cold climate heat pumpfound on the NEEP cc ASHP qualified product list shall be used. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	0.5	N/A
3.4a,d	Closed-loop ground source heat pump; with a minimum COP of 3.3 or Open loop water source heat pump with a maximum pumping hydraulic head of 150 feet and minimum COP of 3.6. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.5	1.0
3.5d	Ductless mini-split heat pump system, zonal control: In homes where the primary space heating system is zonal electric heating, a ductless mini-split heat pump system with a minimum HSPF of 10.0 shall be installed and provide heating to the largest zone of the housing unit. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.5	2.0
3.6a,d	Air-source, centrally ducted heat pump with minimum HSPF of 11.0. A centrally ducted air source cold climate variable capacity heat pump (cc VHP) found on the NEEP cc VCHP qualified product list with a minimum of 10 HSPF may be used to satisfy this requirement. In areas where the winter design temperature as specified in Appendix RC is 23°F or below, an air source centrally ducted heat pump shall be a cold climate variable capacity heat pump as listed on the NEEP qualified product list. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.	1.0	N/A
3.7a,d	Ductless split system heat pumps with no electric resistance heating in the primary living areas. A ductless heat pump system with a minimum HSPF of 10 shall be sized and installed to provide heat to entire dwelling unit at the design outdoor air temperature. Exception: In homes with total heating loads of 24,000 or less using multi-zone mini-split systems with nominal ratings of 24,000 or less, the minimum HSPF to claim this credit shall be 9 HSPF. To qualify to claim this credit, the building permit drawings shall specify the option being selected, the heated floor area calculation, the heating equipment type(s), the minimum equipment efficiency, and total installed heat capacity (by equipment type).	2.0	3.0
3.8a,d	Air-to-water heat pump with minimum COP of 3.2 at 47°F, rated in accordance with AHRI 550/590 by an accredited or certified testing lab. To qualify to claim this credit, the building permit drawings shall specify the option being selected, the heated floor area calculation, the heating equipment type(s), the minimum equipment efficiency, and total installed heat capacity (by equipment type).	1.0	N/A
3.9c	Connected thermostat meeting ENERGY STAR Certified Smart Thermostats/EPA ENERGY STAR specifications. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the thermostat model.
4. HIGH EFFICIENCY HVAC DISTRIBUTION SYSTEM OPTIONS
4.1	HVAC equipment and associated duct system(s) installation shall comply with the requirements of Section R403.3.2. Electric resistance heat, hydronic heating and ductless heat pumps are not permitted under this option. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and shall show the location of the heating and cooling equipment and all the ductwork.	0.5	N/A
5. EFFICIENT WATER HEATING OPTIONS Only one option from Items 5.3 through 5.5 may be selected in this category. Items 5.1 and 5.2 may be combined with any option.
5.1	A drain water heat recovery unit(s) shall be installed, which captures wastewater heat from at least two showers, including tub/shower combinations. It is acceptable, but not required, for sink water to be connected. Unit shall have a minimum efficiency of 40% if installed for equal flow or a minimum efficiency of 54% if installed for unequal flow. Such units shall be rated in accordance with CSA B55.1 or IAPMO IGC 346-2017 and be so labeled. To qualify to claim this credit, the building permit drawings shall include a plumbing diagram that specifies the drain water heat recovery units and the plumbing layout needed to install it. Labels or other documentation shall be provided that demonstrates that the unit complies with the standard.	0.5	0.5
5.2	For Compact Hot Water Distribution system credit, the volume shall store not more than 16 ounces of water between the nearest source of heated water and the termination of the fixture supply pipe where calculated using Section R403.5.2. Construction documents shall indicate the ounces of water in piping between the hot water source and the termination of the fixture supply. When the hot water source is the nearest primed plumbing loop or trunk, this must be primed with an On Demand recirculation pump and must run a dedicated ambient return line from the furthest fixture or end of loop to the water heater. To qualify for this credit, the dwelling must have a minimum of 1.5 bathrooms.	0.5	0.5
5.3	Solar water heating supplementing a minimum standard water heater. Solar water heating will provide a rated minimum savings of 85 therms or 2000 kWh based on the Solar Rating and Certification Corporation (SRCC) Annual Performance of OG-300 Certified Solar Water Heating Systems or Water heater heated by ground source heat pump meeting the requirements of Option 3.3. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency and, for solar water heating systems, the calculation of the minimum energy savings.	1.0	1.0
5.4	Water heating system shall include one of the following: Electric heat pump water heater meeting the standards for Tier III of NEEA's advanced water heating specification or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier III of NEEA's advanced water heating specification, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	2.0	2.5
5.5	Water heating system shall include one of the following: Electric heat pump water heater with a minimum UEF of 2.9 and utilizing a split system configuration with the air-to-refrigerant heat exchanger located outdoors. Equipment shall meet Section 4, requirements for all units, of the NEEA standard Advanced Water Heating Specification with the UEF noted above or For R-2 Occupancy, electric heat pump water heater(s), meeting the standards for Tier III of NEEA's advanced water heating specification and utilizing a split system configuration with the air-to-refrigerant heat exchanger located outdoors, shall supply domestic hot water to all units. If one water heater is serving more than one dwelling unit, all hot water supply and recirculation piping shall be insulated with R-8 minimum pipe insulation. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.	2.5	3.0
6. RENEWABLE ELECTRIC ENERGY OPTION
6.1	For each 600 kWh of electrical generation per housing unit provided annually by on-site wind or solar equipment a 0.5 credit shall be allowed, up to 4.5 credits. Generation shall be calculated as follows: For solar electric systems, the design shall be demonstrated to meet this requirement using the National Renewable Energy Laboratory calculator PVWATTs or approved alternate by the code official. Documentation noting solar access shall be included on the plans. For wind generation projects designs shall document annual power generation based on the following factors: The wind turbine power curve; average annual wind speed at the site; frequency distribution of the wind speed at the site and height of the tower. To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the photovoltaic or wind turbine equipment type, provide documentation of solar and wind access, and include a calculation of the minimum annual energy power production.	0.5 – 4.5	0.5 – 4.5
7. APPLIANCE PACKAGE OPTION
7.1	All of the following appliances shall be new and installed in the dwelling unit and shall meet the following standards: 1. Dishwasher, standard - Energy Star rated, Most Efficient 2021 or Dishwasher, compact – Energy Star rated (Version 6.0) 2. Refrigerator (if provided) - Energy Star rated (Version 5.1) 3. Washing machine (Residential) - Energy Star rated (Version 8.1) 4. Dryer - Energy Star rated, Most Efficient 2022 To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the appliance type and provide documentation of Energy Star compliance. At the time of inspection, all appliances shall be installed and connected to utilities. Dryer ducts and exterior dryer vent caps are not permitted to be installed in the dwelling unit.	0.5	1.5

a	An alternative heating source sized at a maximum of 0.5 Watts/ft2 (equivalent) of heated floor area or 500 Watts, whichever is bigger, may be installed in the dwelling unit.
b	See Section R401.1 and residential building in Section R202 for Group R-2 scope.
c	Option 3.9 can only be taken with Options 3.1 and 3.2.
d	This option may only be claimed if serving System Type 4 or 5 from Table R406.2.

Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency and appear in the Register pursuant to the requirements of RCW 34.08.040.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-50100Section R501—General.

R501.1 Scope. The provisions of this chapter shall control the alteration, repair, addition and change of occupancy of existing buildings and structures.

R501.1.1 ((Additions, alterations, or repairs. Additions, alterations, or repairs to an existing building, building system or portion thereof shall comply with Sections R502, R503 or R504.))General. Except as specified in this chapter, this code shall not be used to require the removal, alteration, or abandonment of, nor prevent the continued use and maintenance of, an existing building or building system lawfully in existence at the time of adoption of this code. Unaltered portions of the existing building or building supply system shall not be required to comply with this code.

R501.1.2 Thermostats for accessory dwelling units. Where a separate dwelling unit, that provides independent facilities for living, sleeping, cooking, bathing and sanitation, is established within or attached to an existing dwelling unit, the heating and cooling for the newly-created dwelling unit shall be controllable with a separate programmable thermostat in accordance with Section R403.1.1.

R501.2 ((Existing buildings. Except as specified in this chapter, this code shall not be used to require the removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing building or building system lawfully in existence at the time of adoption of this code.))Compliance.Additions, alterations, repairs or changes of occupancy to, or relocation of, an existing building, building system or portion thereof shall comply with Sections R502, R503, R504 or R505, respectively, in this code. Changes where unconditioned space is changed to conditioned space shall comply with Section R502.

R501.3 Maintenance. Buildings and structures, and parts thereof, shall be maintained in a safe and sanitary condition. Devices and systems that are required by this code shall be maintained in conformance with the code edition under which installed. The owner or the owner's authorized agent shall be responsible for the maintenance of buildings and structures. The requirements of this chapter shall not provide the basis for removal or abrogation of energy conservation, fire protection and safety systems and devices in existing structures.

R501.4 Compliance.Alterations, repairs, additions and changes of occupancy to, or relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in this code and the International Residential Code, International Building Code, International Existing Building Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, Uniform Plumbing Code, International Property Maintenance Code, and NFPA 70.

R501.5 New and replacement materials. Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted for repairs, provided hazards to life, health or property are not created. Hazardous materials shall not be used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and location.

R501.6 Historic buildings. The code official may modify the specific requirements of this code for historic buildings and require alternate provisions which will result in a reasonable degree of energy efficiency. This modification may be allowed for those buildings or structures that are listed in the state or national register of historic places; designated as a historic property under local or state designation law or survey; certified as a contributing resource with a national register listed or locally designated historic district; or with an opinion or certification that the property is eligible to be listed on the national or state register of historic places either individually or as a contributing building to a historic district by the state historic preservation officer or the keeper of the National Register of Historic Places.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-50200Section R502—Additions.

R502.1 General. Additions to an existing building, building system or portion thereof shall conform to the provisions of this code as those provisions relate to new construction without requiring the unaltered portion of the existing building or building system to comply with this code, except as specified in this chapter. Additions shall not create an unsafe or hazardous condition or overload existing building systems. An addition shall be deemed to comply with this code where the addition alone complies, where the existing building and addition comply with this code as a single building, or where the building with the addition uses no more energy than the existing building. Additions shall be in accordance with Section R502.1.1 or R502.1.2.

R502.1.1 Small additions.Additions not greater than 150 square feet (13.9 m2) shall not be required to comply with Section R406.

R502.2 Change in space conditioning. Any nonconditioned or low-energy space that is altered to become conditioned space shall be required to be brought into full compliance with this code.

EXCEPTION:

Where the total building performance option in Section R405 is used to comply with this section, the annual energy use of the proposed design is permitted to be 110 percent of the annual energy use otherwise allowed by Section R405.3.

R502.3 Prescriptive compliance. Additions shall comply with Sections ((R502.1.1.1))R502.3.1 through ((R502.1.1.4))R502.3.4.

((R502.1.1.1))R502.3.1 Building envelope. New building envelope assemblies that are part of the addition shall comply with Sections R402.1, R402.2, R402.3.1 through R402.3.5, and R402.4.

EXCEPTION:

Where nonconditioned space is changed to conditioned space, the building envelope of the addition shall comply where the UA, as determined in Section ((R402.1.4))R402.1.5, of the existing building and the addition, and any alterations that are part of the project, is less than or equal to UA generated for the existing building.

((R502.1.1.2))R502.3.1.1 Existing ceilings with attic spaces. Where an addition greater than 150 square feet (9.2 m2) adjoins existing ceilings with attic spaces, the existing attic spaces shall comply with Section R402.

R502.3.2 Heating and cooling systems. ((New heating, cooling and duct systems that are part of the))HVAC ducts newly installed as part of anaddition shall comply with Section R403.

EXCEPTION:	The following need not comply with the testing requirements of Section R403.3.3:
	1. Additions of less than ((750))150 square feet.
	2. Duct systems that are documented to have been previously sealed as confirmed through field verification and diagnostic testing in accordance with procedures in WSU RS-33.
	3. ((Ducts with less than 40 linear feet in unconditioned spaces.
	4.)) Existing duct systems constructed, insulated or sealed with asbestos.

((R502.1.1.3))R502.3.3 Service hot water systems. New service hot water systems that are part of the addition shall comply with Section R403.5.

((R502.1.1.4))R502.3.4 Lighting. New lighting systems that are part of the addition shall comply with Section 404.1.

((R502.1.2))R502.4 Existing plus addition compliance (((Simulated Performance Alternative))Total Building Performance). Where nonconditioned space is changed to conditioned space the addition shall comply where the annual energy use of the addition and the existing building, and any alterations that are part of the project, is less than or equal to the annual energy use of the existing building when modeled in accordance with Section R405. The addition and any alterations that are part of the project shall comply with Section R405 in its entirety.

AMENDATORY SECTION(Amending WSR 20-21-081, filed 10/19/20, effective 2/1/21)

WAC 51-11R-50300Section R503—Alterations.

R503.1 General.Alterations to any building or structure shall comply with the requirements of the code for new construction, without requiring the unaltered portions of the existing building or building system to comply with this code. Alterations shall be such that the existing building or structure is no less conforming to the provisions of this code than the existing building or structure was prior to the alteration.

((Alterations to an existing building, building system or portion thereof shall conform to the provisions of this code as they relate to new construction without requiring the unaltered portions of the existing building or building system to comply with this code.))Alterations shall not create an unsafe or hazardous condition or overload existing building systems.

Alterations shall be such that the existing building or structure uses no more energy than the existing building or structure prior to the alteration. Alterations to existing buildings shall comply with Sections R503.1.1 through R503.2.

The code official may approve designs of alterations which do not fully conform to all of the requirements of this code where in the opinion of the code official full compliance is physically impossible and/or economically impractical and:

The alteration improves the energy efficiency of the building; or

The alteration is energy efficient and is necessary for the health, safety, and welfare of the general public.

R503.1.1 Building envelope. Building envelope assemblies that are part of the alteration shall comply with Section ((R402.1.1 or R402.1.4))R402.1.3 or R402.1.5, Sections R402.2.1 through R402.2.11, R402.3.1, R402.3.2, R402.4.3, and R402.4.4.

EXCEPTION:	The following alterations need not comply with the requirements for new construction provided the energy use of the building is not increased:
	1. Storm windows installed over existing fenestration.
	2. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are filled with insulation. 2 x 4 framed walls shall be insulated to a minimum of R-15 and 2 x 6 framed walls shall be insulated to a minimum of R-21.
	3. Construction where the existing roof, wall or floor cavity is not exposed.
	4. Roof recover.
	5. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during reroofing shall be insulated either above or below the sheathing.
	6. Surface-applied window film installed on existing single pane fenestration assemblies to reduce solar heat gain provided the code does not require the glazing fenestration to be replaced.

R503.1.1.1 Replacement fenestration. Where some or all of an existing fenestration unit is replaced with a new fenestration product, including sash and glazing, the replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table ((R402.1.1))R402.1.3. Where more than one replacement fenestration unit is being installed, an area-weighted average of the U-factor and SHGC of all replacement fenestration shall be permitted to be used to demonstrate compliance.

R503.1.2 Heating and cooling systems. New heating, cooling and duct systems that are part of the alteration shall comply with Section R403.

EXCEPTIONS:	1. Where ducts from an existing heating and cooling system are extended, duct systems with less than 40 linear feet in unconditioned spaces shall not be required to be tested in accordance with Section R403.2.2.
	2. Existing duct systems constructed, insulated or sealed with asbestos.
	3. Replacements of space heating equipment shall not be required to comply with Section R403.13 where the rated capacity of the new equipment does not exceed the rated capacity of the existing equipment.

R503.1.3 Service hot water systems. New service hot water systems that are part of the alteration shall comply with Section R403.5.

EXCEPTIONS:	1. Replacement of water heating equipment shall not be required to comply with Section R403.5.5.
	2. Replacement of water heating equipment shall not be required to comply with Section R403.5.7 where the rated capacity of the new equipment does not exceed the rated capacity of the existing equipment.

R503.1.4 Lighting. New lighting systems that are part of the alteration shall comply with Section R404.1.

EXCEPTION:

Alterations that replace less than ((50))10 percent of the luminaires in a space, provided that such alterations do not increase the installed interior lighting power.

((R503.2 Change in space conditioning. Any nonconditioned or low-energy space that is altered to become conditioned space shall be required to be brought into full compliance with this code.

EXCEPTION:

Where the simulated performance option in Section R405 is used to comply with this section, the annual energy use of the proposed design is permitted to be 110 percent of the annual energy use otherwise allowed by Section R405.3.))

AMENDATORY SECTION(Amending WSR 16-02-127, filed 1/6/16, effective 7/1/16)

WAC 51-11R-50500Section R505—Change of occupancy or use.

R505.1 ((Change in occupancy or use.))General. Any space not within the scope of Section R101.2 which is converted to space that is within the scope of Section R101.2 shall be brought into full compliance with this code.

Spaces undergoing a change in occupancy that would result in an increase in demand for either fossil fuel or electrical energy shall comply with this code.

Any space that is converted to a dwelling unit or portion thereof from another use or occupancy shall comply with this code.

EXCEPTION:

R505.1.1 Unconditioned space. Any unconditioned or low-energy space that is altered to become a conditioned space shall comply with Section R502.

AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)

WAC 51-11R-51000Chapter 6—Referenced standards.

This chapter lists the standards that are referenced in various sections of this document. The standards are listed herein by the promulgating agency of the standard, the standard identification, the effective date and title, and the section or sections of this document that reference the standard. The application of the referenced standards shall be as specified in Section R106.

AAMA	American Architectural Manufacturers Association
	1827 Walden Office Square
	Suite 550
	Schaumburg, IL 60173-4268
Standard reference number	Title		Referenced in code section number
AAMA/WDMA/CSA 101/I.S.2/A C440-17	North American Fenestration Standard/Specifications for Windows, Doors and Unit Skylights	. . . . . . . .	R402.4.3
ACCA	Air Conditioning Contractors of America
	2800 Shirlington Road, Suite 300
	Arlington, VA 22206
Standard reference number	Title		Referenced in code section number
Manual J-16	Residential Load Calculation Eighth Edition	. . . . . . . .	R403.7
Manual S-14	Residential Equipment	. . . . . . . .	R403.7
ANSI	American National Standards Institute 25 West 43rd Street, 4th Floor New York, NY 10036
Standard reference number	Title		Referenced in code section number
Z21.50-2016/CSA 2.22-2016	Vented Decorative Gas Appliances	. . . . . . . .	R402.4.2.1, R403.1.3
Z21.88-2017/CSA 2.33-2017	Vented Gas Fireplace Heaters	. . . . . . . .	R402.4.2.1
APSP	The Association of Pool and Spa Professionals
	2111 Eisenhower Avenue, Suite 500
	Alexandria, VA 22206
Standard reference number	Title		Referenced in code section number
ANSI/APSP/ICC ((14-2014))14-2019	American National Standard for Portable Electric Spa Energy Efficiency	. . . . . . . .	R403.11
ANSI/APSP/ICC 15a-2011	American National Standard for Residential Swimming Pool and Spa Energy Efficiency—Includes Addenda A approved January 9, 2013	. . . . . . . .	R403.12
ASHRAE	American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
	1791 Tullie Circle, N.E.
	Atlanta, GA 30329-2305
Standard reference number	Title		Referenced in code section number
((ASHRAE-2017)) ASHRAE-2021	ASHRAE Handbook of Fundamentals	. . . . . . . .	((R402.1.4))R402.1.5, Table R405.5.2(1)
ASHRAE 193-2010 (RA 2014)	Method of Test for Determining the Airtightness of HVAC Equipment	. . . . . . . .	R403.3.2.1
ASTM	ASTM International
	100 Barr Harbor Drive
	West Conshohocken, PA 19428-2859
Standard reference number	Title		Referenced in code section number
C1363-11	Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus	. . . . . . . .	R303.1.4.1
((E 283-04))E 283-2004 (2012)	Test Method for Determining the Rate of Air Leakage Through Exterior Windows, Curtain Walls and Doors Under Specified Pressure Differences Across the Specimen	. . . . . . . .	R402.4.5
((E779-10))E779-2010 (2018)	Standard Test Method for Determining Air Leakage Rate by Fan Pressurization	. . . . . . . .	R402.4.1.2
E1554/E1554M-E2013	Standard Test Method for Determining Air Leakage of Air Distribution Systems by Fan Pressurization	. . . . . . . .	R403.3.5
((E1827-11)) E1827-2011 (2017)	Standard Test Methods for Determining Airtightness of Building Using an Orifice Blower Door	. . . . . . . .	R402.4.1.2
E2178-2013	Standard Test Method for Air Permeance of Building Materials	. . . . . . . .	R303.1.5
E3158-2018	Standard Test Method for Measuring the Air Leakage Rate of a Large or Multizone Building	. . . . . . . .	R402.4.1.2
CSA	Canadian Standards Association
	5060 Spectrum Way
	Mississauga, Ontario, Canada L4W 5N6
Standard reference number	Title		Referenced in code section number
AAMA/WDMA/CSA 101/I.S.2/A440-17	North American Fenestration Standard/Specification for Windows, Doors and Unit Skylights	. . . . . . . .	R402.4.3
CSA 55.1-2015	Test Method for Measuring Efficiency and Pressure Loss of Drain Water Heat Recovery Systems	. . . . . . . .	R403.5.4, Table R406.2
CSA 55.2-2015	Drain Water Heat Recovery Units	. . . . . . . .	R403.5.4
CSA P.4.1-15	Testing Method for Measuring Annual Fireplace Efficiency	. . . . . . . .	R402.4.2.1
DASMA	Door and Access Systems Manufacturers Association
	1300 Sumner Avenue
	Cleveland, OH 44115-2851
((105-2016))105-2017	Test Method for Thermal Transmittance and Air Infiltration of Garage Doors and Rolling Doors	. . . . . . . .	R303.1.3
HVI	Home Ventilating Institute
	1000 North Rand Road, Suite 214
	Wauconda, IL 60084
((916-09))916-18	Airflow Test Procedure	. . . . . . . .	R303.1.3
ICC	International Code Council, Inc.
	500 New Jersey Avenue, N.W.
	6th Floor
	Washington, DC 20001
Standard reference number	Title		Referenced in code section number
ANSI/APSP/ICC 14-2019	American National Standard for Portable Electric Spa Energy Efficiency	. . . . . . . .	R403.11
ANSI/APSP/ICC 15a-2011	American National Standard for Residential Swimming Pool and Spa Energy Efficiency—Includes Addenda A approved January 9, 2013	. . . . . . . .	R403.12
ANSI/RESNET/ICC 380—2019	Standard for Testing Airtightness of building, Dwelling Unit and Sleeping Unit Enclosures; Airtightness of Heating and Cooling Air Distribution Systems, and Airflow of Mechanical Ventilation Systems	. . . . . . . .	R402.4.1.2
((IBC-17))IBC-21	International Building Code	. . . . . . . .	R201.3, R303.2, R402.11, R4501.4
ICC 400-17	Standard on the Design and Construction of Log Structures	. . . . . . . .	Table R402.1.1
ICC 500-2020	ICC/NSSA Standard for the Design and Construction of Storm Shelters	. . . . . . . .	R402.5
((IFC-17))IFC-21	International Fire Code	. . . . . . . .	R201.3, R501.4
((IFGC-17))IFGC-21	International Fuel Gas Code	. . . . . . . .	R201.3, R501.4
((IFGC-17))IFGC-21	International Mechanical Code	. . . . . . . .	R201.3, R403.3.2, R403.6, R501.4
((IPMC-17))IPMC-21	International Property Maintenance Code	. . . . . . . .	R501.4
((IRC-17))IRC-21	International Residential Code	. . . . . . . .	R104.2.1, R201.3, R303.2, R401.2, R403.2.2, R403.5, R406.1, R406.2, Table R406.2
IEEE	The Institute of Electrical and Electronic Engineers, Inc.
	3 Park Avenue
	New York, NY 10016-5997
Standard reference number	Title		Referenced in code section number
515.1-2012	IEEE Standard for the Testing, Design, Installation and Maintenance of Electrical Resistance Trace Heating for Commercial Applications	. . . . . . . .	R403.5.1.2
ISO	International Organization for Standardization
	1, rue de Varembe, Case postale 56, CH-1211
	Geneva, Switzerland
Standard reference number	Title		Referenced in code section number
ISO/IEC 17024-212	Conformity Assessment: General requirements for bodies operating certification of persons	. . . . . . . .	R402.4.1.2
NEEA	Northwest Energy Efficiency Alliance
	421 S.W. 6th Ave., Suite 600
	Portland, OR 97204
Standard reference number	Title		Referenced in code section number
NEEA-2011	Northern Climate Specification for Heat Pump Water Heaters, Vers. 4.0	. . . . . . . .	Table R406.2
NEEP	Northeast Energy Efficiency Partnership, Inc.
	24 School Street, 2nd Floor
	Boston, MA 02108-4314
Standard reference number	Title		Referenced in code section number
ccASHP Version 3.1	Cold Climate Air Source Heat Pump (ccASHP) Product List and Specifications: https://neep.org/heating-electrification/ccashp-specification-product-list	. . . . . . . .	Table R406.3
NEMA	National Electrical Manufacturers Association
	1300 17th Street N No. 900
	Arlington, VA 22209
Standard reference number	Title		Referenced in code section number
OS4-2016	Requirements for Air-Sealed Boxes for Electrical and Communications Applications	. . . . . . . .	R402.4.6
NFPA	National Fire Protection Association
	1 Batterymarch Park
	Quincy, MA 02169-7417
Standard reference number	Title		Referenced in code section number
70-20	National Electrial Code	. . . . . . . .	R501.4
NFRC	National Fenestration Rating Council, Inc.
	6305 Ivy Lane, Suite 140
	Greenbelt, MD 20770
Standard reference number	Title		Referenced in code section number
((100-2010))100-2020	Procedure for Determining Fenestration Products U-factors	. . . . . . . .	R303.1.3
((200-2010))200-2020	Procedure for Determining Fenestration Product Solar Heat Gain Coefficients and Visible Transmittance at Normal Incidence	. . . . . . . .	R303.1.3
((400-2010))400-2020	Procedure for Determining Fenestration Product Air Leakage	. . . . . . . .	R402.4.3
UL	Underwriters Laboratory
	333 Pfingsten Road
	Northbrook, IL 60062
Standard reference number	Title		Referenced in code section number
UL 127-11	Factory Built Fireplace	. . . . . . . .	R402.4.2
UL 515-11	Electric Resistance Heat Tracing for Commercial and Industrial Applications	. . . . . . . .	R403.5.1.2
UL 907-94	Fireplace Accessories (with revisions through April 2010)	. . . . . . . .	R402.4.2
US-FTC	United States-Federal Trade Commission
	600 Pennsylvania Avenue N.W.
	Washington, DC 20580
Standard reference number	Title		Referenced in code section number
C.F.R. Title 16 (((May 31, 2005)))(2015)	R-value Rule	. . . . . . . .	Rule R303.1.4
WDMA	Window and Door Manufacturers Association
	1400 East Touhy Avenue, Suite 470
	Des Plaines, IL 60018
Standard reference number	Title		Referenced in code section number
AAMA/WDMA/CSA ((101/I.S.2/A440-11)) 101/I.S.2/A440-17	North American Fenestration Standard/Specification for Windows, Doors and Unit Skylights	. . . . . . . .	R402.4.3
WSU	Washington State University Energy Extension Program
	905 Plum Street S.E., Bldg 3
	P.O. Box 43165
	Olympia, WA 98506-3166
Standard reference number	Title		Referenced in code section number
WSU RS 33	Duct Testing Standard for New and Existing Construction Publication No. WSUEEP15-016	. . . . . . . .	R403.3.3

	Proposed Section and Title	Type of Change	Description
1.	R402.1.2 Insulation and fenestration criteria	2021 IECC change	Section R402 was revised to establish the U-factor table as the default performance basis, with the R-value as an alternate, rather than the other way around.
2.	Table R402.1.2 Insulation and fenestration requirements by component	2021 IECC change/code change (21-GP2-079)	The U-factor table was moved to be the first referenced table. Two values within the table were changed: the ceiling U-factor went from 0.026 to 0.024 in the 2021 IECC; the fenestration U-factor went from 0.30 to 0.28 via code change proposal.
3.	Table R402.1.3 Insulation minimum R-values and fenestration requirements by component	2021 IECC change/code change (21-GP2-079)	The R-value had four values within the table changed: the fenestration U-factor went from 0.30 to 0.28 via code change proposal; and in the 2021 IECC, the ceiling U-factor went from R-49 to R-60, the wood frame wall value went from 21 int. to 20+5 or 13+10, and the slab insulation depth changed from two feet to four feet.
4.	R403.3.5/R403.3.6 Duct testing	2021 IECC change	The exception for ducts within the conditioned space was removed. The ducts must now be tested but are allowed double the leakage rate per Section R403.3.6.
5.	Table R403.6.1 Mechanical ventilation system fan efficacy	2021 IECC change	The table was edited for clarity and the fans redefined by type rather than installed location. The efficacy requirements were updated to the Energy Star Version 4.0 requirements.
6.	R403.6.2 Testing	2021 IECC change	A new requirement was added to the 2021 IECC requiring that the mechanical ventilation be tested and verified to meet the minimum flow rate requirements.
7.	R404 Electrical power and lighting	2021 IECC change	This section was expanded significantly to include lighting controls for both interior (R404.2) and exterior lighting (R404.3). Exterior lighting must follow the requirements in the commercial provisions (R404.1.1). Finally, all permanently installed lighting fixtures are required to contain high efficacy lighting sources.
8.	R503.1.4 Lighting	2021 IECC code change	The threshold for lighting to comply with Section R404.1 was decreased from 50 percent replacement to 10 percent replacement.
9.	R503.2 Change in space conditioning	2021 IECC change	This section was moved to R502, Additions, since the change in space conditioning results in additional living space.

LOG NUMBER	PROPOSED SECTION AND TITLE	TYPE OF CHANGE	DESCRIPTION
21-GP2-084	R202 Definition "Residential building"	Code change (21-GP2-084)	This definition change alters the scope of the Washington State Energy Code, Residential Provisions to resemble more closely that of the International Residential Code. Multifamily buildings with dwellings directly accessed from the outdoors will remain in the residential provisions, but other R-2 buildings are moved under the commercial provisions.
21-GP2-084	R401.1 Scope	Code change (21-GP2-084)	The scope of the Washington State Energy Code, Residential Provisions was changed to resemble more closely the scope of the International Residential Code. Multifamily buildings with dwellings directly accessed from the outdoors will remain in the residential provisions, but other R-2 buildings are moved under the commercial provisions.
21-GP2-079	Table R402.1.2/ R402.1.3 Insulation and fenestration requirements by component	Code change (21-GP2-079)	This proposal changes the fenestration U-factor from 0.30 to 0.28 in both tables.
21-GP2-011	R402.1.4 R-value computation	Code change (editorial) (21-GP2-011)	The code change removes a redundant sentence from the middle of the IECC language.
21-GP2-012	Table R402.4.1.1 Air barrier, air sealing and insulation installation	Code change (editorial) (21-GP2-012)	This code change revises the new IECC footnote b for clarity.
21-GP2-088 21-GP2-082	R402.4.1.2 Testing	Code change (21-GP2-082. 21-GP2-088)	The specifics on the testing standard were moved from the exception into the main body of the section and the test must include information on the time, date and location where performed. Requirements were also added that the testing personnel be trained by an accredited program. The second exception from the second set of exceptions was moved to Section R402.4.1.3. The volume adjustment capping the ceiling height at 8.5 feet was removed.
21-GP2-082	R402.4.1 Building thermal envelope air leakage	Code change (21-GP2-082)	"Air leakage" is added to the title for clarity. An additional subsection is added so the section references are updated.
21-GP2-082 21-GP2-089	R402.4.1.3 Leakage rate	Code change (21-GP2-082, 21-GP2-089)	A new set of subsections was added to separate out the requirements for single family and multifamily dwelling air leakage testing. The maximum leakage rate was reduced to 3 air changes per hour for single family and 0.25 cfm (the same as the commercial requirement) for multifamily.
21-GP2-081	R402.4.2 Fireplaces	Code change/editorial (21-GP2-081)	This section was moved to R402.3.6.
	R402.4.2.1 Gas fireplace efficiency	Code change/editorial (21-GP2-081)	This section was moved to Section R403.7.2.
	R402.4.4 Combustion air openings	Code change/editorial (21-GP2-081)	This section was moved to R402.3.5.
21-GP2-015	R403.12 Residential pools and permanent residential spas	Code change/editorial (21-GP2-015)	Removes "Where installed," at the beginning of the revised IECC section. (Note: no change is shown in R403.5.4 as ICC added this language for the 2021 code, but it was removed via 014, so there is no actual change.)
21-GP2-013	R403.5.1.1 Demand recirculation water systems serving an individual dwelling unit	Code change/editorial (21-GP2-013)
21-GP2-014	R403.5.4 Drain water heat recovery	Code change/editorial (21-GP2-014)
21-GP2-065	R403.13 Heat pump space heating	Code change (21-GP2-065)	This new section requires that space heating be provided by a heat pump—either gas or electric—as a method to reduce greenhouse gas emissions and save energy. There are exceptions provided for dwellings with small heating loads and allowances for supplementary heating following the requirements of Section R403.1.2.
	Table R405.4.2(1) Specifications for the standard reference and proposed designs	Code change (21-GP2-065)	Heating system is revised to align with the baseline of heat pump heating introduced in this code through 21-GP2-065.
	R503.1.2 Heating and cooling systems	Code change (21-GP2-065)	An exception was added to this section to state that replacement heating equipment is not required to comply with the heat pump requirement as long as it does not exceed the heating capacity of the equipment being replaced.
21-GP2-066	R403.5.7 Heat pump water heating	Code change (21-GP2-066)	This new section requires that service water heaters in single family dwellings, duplexes and townhouses be provided by heat pump water heaters. Exceptions are provided for small water heaters, small dwelling units, supplemental water heating systems, and some renewable energy systems. This includes allowances for both gas and electric heat pump water heaters.
	R403.5.7.1 Supplementary heat for heat pump water heating systems	Code change (21-GP2-066)	This is a support section for R403.5.7 and sets requirements for when a supplemental water heating system can be used with the heat pump water heater.
	Table R405.4.2(1) Specifications for the standard reference and proposed designs	Code change (21-GP2-066)	Service water heating was revised to align with the baseline of heat pump water heating as introduced in this code through 21-GP2-066.
	R503.1.3 Service hot water systems	Code change (21-GP2-066)	An exception was added to this section to state that replacement water heating equipment is not required to comply with the heat pump requirement as long as it does not exceed the heating capacity of the equipment being replaced.
21-GP2-032	R403.3.4.1 Sealed air handler	Code change (21-GP2-032)	This change requires the air handler to be located within the conditioned space.
21-GP2-049	R403.4.1 Protection of piping insulation	Code change (21-GP2-049)	Clarification of the intent or equipment maintenance, along with a requirement that the insulation be removable near the equipment requiring maintenance.
21-GP2-080	R403.5.5 Water heater installation location	Code change (21-GP2-080)	This section requires that water heaters be located within conditioned space except for highly efficient water heaters where the standby losses are overcome by the efficiency of the unit performance.
21-GP2-046	R403.5.2 Water volume determination (new)	Code change (21-GP2-046)	This section just provides the reference and procedure for determining the volume of water in piping when selecting one of the new options for credits in Section R406. This is not a base code requirement.
21-GP2-046	Table R406.3 Energy credits	Code change (21-GP2-046)	New Option 5.2 provides half a credit for compact hot water distribution systems as is required in the commercial energy code provisions and as detailed in Section R403.5.2.
21-GP2-070	Table R405.2(2) Carbon emissions factors	Code change (21-GP2-070)	This table is moved from R405.3 to R405.2(2) and the metric for electricity is changes from 0.80 to 0.44 to better align with the commercial energy code, the Clean Buildings law and the OFM lifecycle cost tool.
21-GP2-073	R406.2 Carbon emission equalization	Code change (21-GP2-073)	The last sentence was removed. It was deemed redundant.
	Table R406.2 Fuel normalization credits	Code change (21-GP2-073)	There are two options being presented for this table. Both options revise the table to include more detailed descriptions of heating systems and supplemental systems. Option 1 is the initial technical advisory group recommendation based on the original proposal and the goal of achieving the required energy savings for the cycle. Option 2 is a revised proposal that takes into account the other code change proposals going forward to public hearing and the changes in equipment values based on the new requirements in the proposed rule.
	R406.3 Additional energy efficiency requirements	Code change (21-GP2-073)	Again, there are two options being presented for this table. Both tables include a new 150 square foot threshold for additions to trigger this requirement. Option 1 is the initial technical advisory group recommendation based on the original proposal and the goal of achieving the required energy savings for the cycle. Option 2 is a revised proposal that takes into account the other code change proposals going forward to public hearing and the reduction in energy use based on the new requirements in the proposed rule.
	Table R406.3 Energy credits	Code change (21-GP2-073)	This section also has two options. For both options, one half point is equivalent to a 600 kWh energy savings. Some options were eliminated due to the fact they are now a part of the base code requirements. Option 1 is the initial technical advisory group recommendation based on the original proposal. The credits are based on the heating system type from Table R406.2. Option 2 is a revised proposal that takes into account the other code change proposals going forward to public hearing. Based on the heat pump space and water heating changes, there is no differentiating between the systems types for point values. Instead, there are options that are just not available with some systems types, as identified by footnote d. Some options are no longer available based on the fact that the base requirements now incorporate the provisions contained therein; some are just adjusted to yield a similar energy savings over the base code, or the point value is changed based on the savings reflected.
21-GP2-022	R401.2 Compliance	Code change (21-GP2-022)	This change corrects an error in the previous code that stated that compliance via Section R405 also required compliance with Section R406. R405 carries its own additional credit weighting and thus is not intended to also comply with Section R406.
21-GP2-022	Table R405.2(1) Mandatory compliance measures for total building performance	Code change (21-GP2-022)	An error is also corrected by removing reference to R406. The additional efficiency is covered by the energy reduction targets in items 2 through 5 of Section R405.2
21-GP2-034	Table R406.3 Energy credits	Code change (21-GP2-0234)	New Option 3.8 allows a half credit for a connected thermostat.
21-GP2-023	Table R406.3 Energy credits	Code change (21-GP2-023)	Option 3.2 requires a cold climate heat pump to be used in areas with a winter design temperature at 23° or below.
21-GP2-024	Table R406.3 Energy credits	Code change (21-GP2-024)	Option 3.5 allows an alternate cold climate 10 HSPF heat pump to be substituted for an 11 HSPF heat pump but will require a cold climate heat pump similar to Option 3.2 in 023, above.
21-GP2-025	Table R406.3 Energy credits	Code change (21-GP2-025)	Option 3.6 also allows a substitution of a 9 HSPF heat pump for the required 10 HSPF in some cases.
21-GP2-050	Table R406.3 Energy credits	Code change (21-GP2-050)	New Option 3.7 provides credit for an air to water heat pump with a COP rating of 3.2.
21-GP2-047	Table R406.3 Energy credits	Code change (21-GP2-047)	New Option 5.2 provides half a credit for compact hot water distribution systems as is required in the commercial energy code provisions and as detailed in Section R403.5.2.
21-GP2-047	R403.5.2 Water volume determination (new)	Code change (21-GP2-047)	This section just provides the reference and procedure for determining the volume of water in piping when selecting one of the new options for credits in Section R406. This is not a base code requirement.
21-GP2-035	R406.3 Additional energy efficiency requirements	Code change (21-GP2-035)	Both options include a new 150 square foot threshold for additions to trigger this requirement.
	R502.1 General (Additions)	Code change/editorial (21-GP2-035)	The phrase "except as specified in this chapter" was added to support the new section R502.3.1.1.
	R502.1.1 Small additions	Code change (21-GP2-035)	A new section was added to exempt small additions (less than 150 ft2) from the requirement to obtain additional energy efficiency credits in Section R406.
	R502.3.1.1 Existing ceilings with attic spaces	Code change (21-GP2-035)	This new section requires that when additions over 150 square feet adjoin existing attic spaces, the existing attic space needs to be brought into full compliance with the envelope provisions in R402.
	R502.3.2 Heating and cooling systems	Code change (21-GP2-035)	The section is reworded for clarity, and exception 1 is correlated with the change in R502.1.1. Former exception 3 is deleted to correlate with the IECC change to require all ducts to be tested.