WSR 20-21-081
PERMANENT RULES
BUILDING CODE COUNCIL
[Filed October 19, 2020, 11:25 a.m., effective February 1, 2021]
Effective Date of Rule: February 1, 2021.
Purpose: To correct various internal references and typographical errors in the 2018 Washington State Energy Code, Residential, chapter 51-11R WAC.
Citation of Rules Affected by this Order: Amending 17.
Statutory Authority for Adoption: RCW 19.27A.045.
Other Authority: Chapter 19.27A RCW.
Adopted under notice filed as WSR 20-12-102 on June 3, 2020.
Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.
Number of Sections Adopted at the Request of a Nongovernmental Entity: New 0, Amended 0, Repealed 0.
Number of Sections Adopted on the Agency's own Initiative: New 0, Amended 17, Repealed 0.
Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.
Number of Sections Adopted using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.
Date Adopted: September 10, 2020.
Diane Glenn
Council Chair
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-10400Section R104Inspections.
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 ((building))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.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-20215Section R202.15O.
OPAQUE DOOR. A door that is not less than 50 percent opaque in surface area.
((PILOT LIGHT, CONTINUOUSLY BURNING. A small gas flame used to ignite gas at a larger burning. Once lit, a continuous pilot light remains in operation until manually interrupted. Pilot light ignition systems with the ability to switch between intermittent and continuous mode are considered continuous.
PILOT LIGHT, INTERMITTENT. A pilot which is automatically ignited when an appliance is called on to operate and which remains continuously ignited during each period of main burner operation. The pilot is automatically extinguished when each main burner operating cycle is completed.
PILOT LIGHT, INTERRUPTED. A pilot which is automatically ignited prior to the admission of fuel to the main burner and which is automatically extinguished after the main flame is established.
PILOT LIGHT, ON-DEMAND. A pilot which, once placed into operation, is intended to remain ignited for a predetermined period of time following an automatic or manual operation of the main burner gas valve.))
AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)
WAC 51-11R-20216Section R202.16—P.
PILOT LIGHT, CONTINUOUSLY BURNING. A small gas flame used to ignite gas at a larger burning. Once lit, a continuous pilot light remains in operation until manually interrupted. Pilot light ignition systems with the ability to switch between intermittent and continuous mode are considered continuous.
PILOT LIGHT, INTERMITTENT. A pilot which is automatically ignited when an appliance is called on to operate and which remains continuously ignited during each period of main burner operation. The pilot is automatically extinguished when each main burner operating cycle is completed.
PILOT LIGHT, INTERRUPTED. A pilot which is automatically ignited prior to the admission of fuel to the main burner and which is automatically extinguished after the main flame is established.
PILOT LIGHT, ON-DEMAND. A pilot which, once placed into operation, is intended to remain ignited for a predetermined period of time following an automatic or manual operation of the main burner gas valve.
PROPOSED DESIGN. A description of the proposed building used to estimate annual energy use for determining compliance based on total building performance.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-30310Section R303.1Identification.
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.
((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.))
R303.1.2 Insulation mark installation. Insulating materials shall be installed such that the manufacturer's R-value mark is readily observable upon inspection.
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.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-30311Table R303.1.3(1)Default glazed fenestration U-factor.
TABLE R303.1.3(1)
DEFAULT GLAZED WINDOW, GLASS DOOR AND SKYLIGHT U-FACTOR
FRAME TYPE
SINGLE PANE
DOUBLE PANE
 
Metal
1.20
0.80
SKYLIGHT
Metal with Thermal Breaka
1.10
0.65
See Table R303.1.3(4)
Nonmetal or Metal Clad
0.95
0.55
 
Glazed Block
0.60
a
Metal Thermal Break = A metal thermal break framed window shall incorporate the following minimum design characteristics:
 
1) The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft2/°F;
 
2) The thermal break material must produce a gap in the frame material of not less than 0.210 inches; and
 
3) All metal framing members of the products exposed to interior and exterior air shall incorporate a thermal break meeting the criteria in ((a) and b)))1) and 2) above.
AMENDATORY SECTION(Amending WSR 13-04-055, filed 2/1/13, effective 7/1/13)
WAC 51-11R-30314Table R303.1.3(4)Default U-factors for skylights.
TABLE R303.1.3(4)
DEFAULT U-FACTORS FOR SKYLIGHTS
 
Frame Type
 
Aluminum Without
Thermal Break
Aluminum With
Thermal Break
Reinforced Vinyl/Aluminum-Clad Wood or Vinyl
Wood or Vinyl-Clad Wood/Vinyl Without Reinforcing
Fenestration Type
Single Glazing
 
 
 
 
 
glass
U-1.58
U-1.51
U-1.40
U-1.18
 
acrylic/polycarb
U-1.52
U-1.45
U-1.34
U-1.11
Double Glazing
 
 
 
 
 
air
U-1.05
U-0.89
U-0.84
U-0.67
 
argon
U-1.02
U-0.86
U-0.80
U-0.64
Double Glazing, e = 0.20
 
 
 
 
 
air
U-0.96
U-0.80
U-0.75
U-0.59
 
argon
U-0.91
U-0.75
U-0.70
U-0.54
Double Glazing, e = 0.10
 
 
 
 
 
air
U-0.94
U-0.79
U-0.74
U-0.58
 
argon
U-0.89
U-0.73
U-0.68
U-0.52
Double Glazing, e = 0.05
 
 
 
 
 
air
U-0.93
U-0.78
U-0.73
U-0.56
 
argon
U-0.87
U-0.71
U-0.66
U-0.50
Triple Glazing
 
 
 
 
 
air
U-0.90
U-0.70
U-0.67
U-0.51
 
argon
U-0.87
U-0.69
U-0.64
U-0.48
Triple Glazing, e = 0.20
 
 
 
 
 
air
U-0.86
U-0.68
U-0.63
U-0.47
 
argon
U-0.82
U-0.63
U-0.59
U-0.43
Triple Glazing, e = 0.20 on 2 surfaces
 
 
 
 
 
air
U-0.82
U-0.64
U-0.60
U-0.44
 
argon
U-0.79
U-0.60
U-0.56
U-0.40
Triple Glazing, e = 0.10 on 2 surfaces
 
 
 
 
 
air
U-0.81
U-0.62
U-0.58
U-0.42
 
argon
U-0.77
U-0.58
U-0.54
U-0.38
Quadruple Glazing, e = 0.10 on 2 surfaces
 
 
 
 
 
air
U-0.78
U-0.59
U-0.55
U-0.39
 
argon
U-0.74
U-0.56
U-0.52
U-0.36
 
krypton
U-0.70
U-0.52
U-0.48
U-0.32
Notes for Table R303.1.3(4)
1.
U-factors are applicable to ((both)) glass and plastic, flat and domed units, all spacers and gaps.
2.
Emissivities shall be less than or equal to the value specified.
3.
Gap fill shall be assumed to be air unless there is a minimum of 90% argon or krypton.
4.
Aluminum frame with thermal break is as defined in footnote 1 to Table R303.1.3(1).
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40220Section R402.2Specific 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 would require R-49 in the ceiling, installing R-38 over 100 percent of the ceiling area requiring insulation shall be deemed to satisfy the requirement for R-49 wherever the full height of uncompressed R-38 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the U-factor alternative approach in Section R402.1.3 and the total UA alternative in Section R402.1.4.
R402.2.1.1 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.
R402.2.3 Eave baffle. For air permeable insulations in vented attics, a baffle shall be installed adjacent to soffit and eave vents. Baffles shall maintain an 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.
R402.2.4 Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces (e.g., 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.
EXCEPTION:
Vertical doors that provide access from conditioned to unconditioned spaces shall be permitted to meet the fenestration requirements of Table R402.1.1.
R402.2.5 Mass walls. Mass walls, where used as a component of the 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.
R402.2.7 Floors. Floor framing cavity insulation shall be installed to maintain permanent contact with the underside of the subfloor decking. 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.
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. 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. 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 ((Reserved.
R402.2.11)) 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-40240Section R402.4Air 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.
R402.4.1 Building thermal envelope. The building thermal envelope shall comply with Sections R402.4.1.1 and R402.4.1.2. 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. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope. Once visual inspection has confirmed sealing (see Table R402.4.1.1), operable windows and doors manufactured by small business shall be 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.
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.
EXCEPTIONS:
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.
R402.4.3 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.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40351Table R403.6.1Mechanical ventilation system fan efficacy.
TABLE R403.6.1
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
For SI: 1 cfm = 28.3 L/min.
a. When tested in accordance with HVI Standard 916.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40360Section R403.7Equipment 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 ((C403.2.3(1), C403.2.3(2), C403.2.3(3), C403.2.3(4), C403.2.3(5), C403.2.3(6), C403.2.3(7), C403.2.3(8) and C403.2.3(9)))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.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40530Section R405.3Performance-based compliance.
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 ((and)) 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.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40551Table R405.5.2(1)Specifications for the standard reference and proposed designs.
TABLE R405.5.2(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
Solar absorptance = 0.75
((Remittance))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, 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
As proposed
As proposed
As proposed
Ceilings
Type: Wood frame
Gross area: Same as proposed
U-factor: From Table R402.1.3
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.
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
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
- 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 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 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 WSECCommercial 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
As proposed
gal/day = 30 + (10 × Nbr)
Thermal distribution systems
Duct insulation: From Section R403.3.3.
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 (((DES))DSE) shall be 1.
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.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40700Section R407Certified passive house.
R407.1 General. Projects shall comply with Section R407.2 or R407.3.
R407.2 Passive House Institute U.S. (PHIUS). Projects shall comply with PHIUS+ 2018 Passive Building Standard, including its USDOE Energy Star and Zero Energy Ready Home co-requisites, and performance calculations by PHIUS-approved software. Projects shall also comply with the provisions of Table R405.2.
R407.2.1 PHIUS documentation. Prior to the issuance of a building permit, the following items must be provided to the ((building))code official:
1. A list of compliance features.
2. A PHIUS precertification letter.
Prior to the issuance of a certificate of occupancy, the following item must be provided to the ((building))code official:
1. A PHIUS+ 2018 (or later) project certificate.
R407.3 Passive House Institute (PHI). Projects shall comply with Low Energy Building Standard, version 9f or later, including performance calculations by PHI-approved software. Projects shall also comply with the provisions of Section R401 through R404.
R407.3.1 PHI documentation. Prior to the issuance of a building permit, the following items must be provided to the ((building))code official:
1. A list of compliance features.
2. A statement from a passive house certifier that the modeled energy performance is congruent with the plans and specifications, and that the modeled performance meets said standard.
Prior to the issuance of a certificate of occupancy, the following item must be provided to the ((building))code official:
1. A PHI Low Energy Building project certificate.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-50100Section R501General.
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. 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.
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 ((building))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-50300Section R503Alterations.
R503.1 General. Alterations to any building or structure shall comply with the requirements of the code for new construction. 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 ((building))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, 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. 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.
R503.1.3 Service hot water systems. New service hot water systems that are part of the alteration shall comply with Section R403.5.
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 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-50400Section R504Repairs.
R504.1 General. Buildings, structures and parts thereof shall be repaired in compliance with Section R501.3 and this section. Work on nondamaged components that is necessary for the required repair of damaged components shall be considered part of the repair and shall not be subject to the requirements for alterations in this chapter. Routine maintenance required by Section R501.3, ordinary repairs exempt from permit, and abatement of wear due to normal service conditions shall not be subject to the requirements for repairs in this section.
The code official may approve designs of repairs which do not fully conform with all of the requirements of this code where in the opinion of the ((building))code official full compliance is physically impossible and/or economically impractical and:
1. The repair improves the energy efficiency of the building; or
2. The repair is energy efficient and is necessary for the health, safety, and welfare of the general public.
R504.2 Application. For the purposes of this code, the following shall be considered repairs.
1. Glass only replacements in an existing sash and frame.
2. Roof repairs.
3. Repairs where only the bulb and/or ballast within the existing luminaires in a space are replaced provided that the replacement does not increase the installed interior lighting power.
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-59000Appendix RBOptional energy efficiency measuresTwo step.
Building owners may choose to use this appendix to achieve an additional 12 percent savings in building energy use. The number of additional energy efficiency credits required by Section R406.3 would be increased by the following amounts:
2.0 credit for each new single-family, two-family and townhouse dwelling unit.
1.0 credit for each new dwelling unit within an R-2 occupancy building.
1.0 credit for each addition smaller than 500 square feet to a single-family, two-family or townhouse dwelling unit.
1.5 credit for each addition of 500 square feet or larger to a single-family, two-family or townhouse dwelling unit.
Where Section R405, Simulated performance alternative, is used, the maximum allowable energy consumption shall be ((92))84 percent of the value calculated according to Section R405.3.