Proposed Residential Energy Code Amendments to the 2018 Code

Heat loss map

The Washington State Building Code Council is currently undergoing a review process for proposed amendments to the state’s 2018 residential energy code. The following proposals have been accepted by both the Council’s Energy Code Technical Advisory Group and the full Council to be moved forward to public comment.

The proposed residential energy code amendments are open for public comment through Sept. 27, 2019. The SBCC will also take public comments in person at hearings in Spokane (Sept. 13) and Olympia (Sept. 27). The anticipated effective date for the 2018 codes is July 1, 2020.

Commenting on the proposals
AIA Washington Council will submit comments on the proposed amendments provided that enough consensus exists among members. While members are encouraged to offer comments directly to the SBCC, we welcome your feedback on any of the proposals and will incorporate it into our comment considerations. You are welcome to offer comments on as few or as many of the proposals as you wish.  If you need additional information, please let Kirsten know.

Comments to the SBCC may be sent in writing or via email to:

Washington State Building Code Council
P.O. Box 41449
Olympia, Washington 98504-1449

Comments to AIA|WA should be sent to Kirsten Smith via email to or by phone at 206-957-1926.

Proposals under consideration
The proposed amendments may be viewed via the links below. Click on the red number in the left-hand column to read the full proposal. If sending comments to the SBCC, please reference the SBCC # in the 2nd column below with your comments.

#SBCC Reference #SummarySBCC Vote
119-WSEC-R01 & R03 (combined)Adding IRC accessory buildings and IBC R-3 accessory buildings to the definition of “residential building”.14-1
219-WSEC-R02Recognize drain water heat recovery devices that are certified and rated to an IAPMO standard for drain water heat recovery.13-1
319-WSEC-R04Correct the language to not require insulation under electric water heaters in heated spaces.14-0
419-WSEC-R07Adds smart thermostats and then changes language to be consistent with the 2018 IECC.12-1
519-WSEC-R08Include whole-house mechanical ventilation test results on permanent certificate.14-0
619-WSEC-R10Provide option to earn a 0.5 energy credits in the prescriptive table for advanced framing and raised heel trusses or rafters.14-0
719-WSEC-R11Requires a programmable thermostat as defined by R403.1.1 be installed in accessory dwelling units.13-0
819-WSEC-R12Adds a footnote to Table R402.1.1 that would allow the use of Table R402.1.1 Insulation and Fenestration Requirements by Component. Provides more flexibility allowing a prescriptive compliance option when existing garages, metal or masonry shops are permitted as converted from unconditioned space to conditioned space for ADU units or non-dwelling buildings such as heated shops. 13-0
919-WSEC-R13Improves on “build tight” documentation of important envelope leakage and duct testing on the certificate.13-0
1019-WSEC-R15Provides option to earn a 0.5 energy credit under section 4 of the prescriptive table for mechanical ductwork that is deeply buried in under attic insulation.6-4-3
1119-WSEC-R17Adds a definition for Ductless Mini-split system to the Energy Code.15-0
1219-WSEC-R18Add a HVAC and service water heating equipment reference tables by reference to equipment performance requirements in the commercial code.14-0
1319-WSEC-R19High efficiency lamps. Removes CFL from the qualified lamps. Creates a uniform standard 65 lumens per watt.12-0
1419-WSEC-R20For the purpose of air leakage testing only, the volume of the living space shall be the conditioned floor area (square feet) multiplied by 8.5 (feet).9-6
1519-WSEC-R21Create consistent and enforceable building envelope section. This change provides clarifications, but not change the requirements of the code.8-2-3
1619-WSEC-R22Upgrade log wall standards to the national IRC requirements.14-0
1719-WSEC-R23Updates Section R406 and requires additional energy efficiency credits. Also amends portions of the prescriptive code, as required, to support proposed revisions to Section R406.9-5
1819-WSEC-R27Establishes a minimum efficiency performance threshold for fireplaces based on the Canadian FE Standard.9-5
1919-WSEC-R28Prohibits the use of standing (or continuous) pilot lights on select gas‐fired appliances.8-6
2019-WSEC-R31Updates Section R406 and requires additional energy efficiency credits. It also amends portions of the prescriptive code, as required, to support proposed revisions to Section R406. This proposal differs from similar proposals being submitted in that it further increases the proposed number of additional energy efficiency credits required.7-6
2119-WSEC-R32Add passive house certification (PHIUS and PHI) as high-level alternate compliance paths on the same level as the R405 Simulated Performance Alternative, as being sufficient to demonstrate energy code compliance without calculation of a standard reference design.9-1-2
2219-WSEC-R33Enhances customer choice by making it easy for homeowners to choose either electric or gas appliances and water heating equipment. By ensuring that a home built with gas or propane can easily accommodate future electric appliances and equipment, this proposal protects homeowners from future costs, should natural gas become less affordable or even unavailable over the life of the building.7-6-2
2319-WSEC-R35Creates a tri-level code by adding two optional appendix chapters, Appendix X which increases energy efficiency by approximately 8 percent and Appendix Y which increases energy efficiency by approximately 16 percent.12-1
2419-WSEC-R36Updates Section R406 based on carbon emissions drawn from the carbon accounting included in the final proposed commercial energy code approved by the SBCC in 2018.10-2-1