WSR 22-10-094
PERMANENT RULES
BUILDING CODE COUNCIL
[Filed May 3, 2022, 5:45 p.m., effective June 3, 2022]
Effective Date of Rule: Thirty-one days after filing.
Purpose: This filing is making corrections to the adopted amendments to the 2018 Washington State Energy Code, Residential Provisions, as adopted by the state building code council on November 8, 2019.
Several typographical and internal reference errors were found in the code after adoption. The following editorial corrections are being made:
1. In Table R405.2, the title for Section R403.3.1 was corrected from "Equipment and system sizing" to "Insulation."
2. In Table R406.3, in Group 2, Air Leakage Control, the IRC section references in Items 2.1, 2.2, 2.3, and 2.4 were corrected and the air leakage rate in Item 2.3 was corrected.
3. In Table R406.3, in Group 4, High Efficiency HVAC Distribution System, the section reference in Item 4.1 was corrected.
Citation of Rules Affected by this Order: Amending WAC 51-11R-40520 and 51-11R-40621.
Statutory Authority for Adoption: RCW 19.27A.045.
Other Authority: Chapter 19.27A RCW.
Adopted under notice filed as WSR 22-06-044 on February 24, 2022.
Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.
Number of Sections Adopted at the Request of a Nongovernmental Entity: New 0, Amended 0, Repealed 0.
Number of Sections Adopted on the Agency's own Initiative: New 0, Amended 2, Repealed 0.
Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.
Number of Sections Adopted using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.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: May 3, 2022.
Tony Doan
Acting Council Chair
OTS-3612.1
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40520Section R405.2—Mandatory requirements.
R405.2 Mandatory requirements. 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.
TABLE R405.2
MANDATORY COMPLIANCE MEASURES FOR SIMULATED PERFORMANCE ALTERNATIVE
Section
Title
Comments
General
R401.3
Certificate
 
Envelope
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
((Equipment and system sizing))
Insulation
 
R403.3.3
Duct testing
 
R403.3.4
Duct leakage
 
R403.3.5
Building cavities
 
R403.4
Mechanical system piping insulation
 
R403.5.1
Heated water circulation and temperature maintenance system
 
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
 
R403.11
Portable spas
 
Electrical Power and Lighting
R404.1
Lighting equipment
 
R404.1.1
Lighting equipment
 
R404.2
Electric readiness
 
Other Requirements
R406
Additional energy efficiency requirements
 
AMENDATORY SECTION(Amending WSR 20-01-047, filed 12/9/19, effective 7/1/20)
WAC 51-11R-40621Table R406.3—Energy credits.
TABLE 406.3
ENERGY CREDITS
OPTION
DESCRIPTION
CREDIT(S)
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 ((M1507.3))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 ((M1507.3))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 ((0.25))0.20 cfm/ft2 maximum at 50 Pascals
and
All whole house ventilation requirements as determined by Section ((M1507.3))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 ((M1507.3))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 ((R403.3.7))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
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.
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.