Answers & Opinions

The Council's Policies and Procedures, in WAC 51-04-060, allows the Council to issue opinions (interpretations) relating to the codes at the request of a local or state official, or their designee, responsible for implementation and enforcement of the specific code provision on which the opinion (interpretation) is requested. For the Council to provide a formal opinion (interpretation), a letter requesting the opinion (interpretation) needs to be submitted by a code official. The final opinions (interpretations) of the Council are advisory only. Opinions (interpretations) that have been finalized are provided through the links to the left.

Some of the opinions (interpretations) refer to illustrations, diagrams, and attached documentation. These supporting documents are not posted on the Web. If you would like a copy of a supporting document please request it from Council Staff.

Answers and Code Interpretations

Year Interpretation Number Code Section Number Code Edition
2025 25-02 R403.6 WA State Energy Code-Residential 2018
2025 25-01 403.4 International Mechanical Code 2018
2024 24-34 C404.2.1.4 Supplemental Water Heating WA State Energy Code-Commercial 2021
2024 24-33 C404.2 Service Water Heating Equipment Efficiency WA State Energy Code-Commercial 2021
2024 24-32 C401/C503 WA State Energy Code-Commercial 2021
2024 24-31 C503 WA State Energy Code-Commercial 2021
2024 24-30 C503.4 WA State Energy Code-Commercial 2021
2024 24-29 R303 WA State Energy Code-Residential 2021
2024 24-28 3103.5 International Fire Code 2021
2024 24-27 R101.2 Adult Family Homes International Residential Code 2021
2024 24-26 R302.2.6 Structural Independence International Residential Code 2021
2024 24-25 1107 / 429 International Building Code 2021
2024 24-24 Table C403.3.2(5). Minimum efficiency for warm-air furnaces and unit heaters WA State Energy Code-Commercial 2021
2024 24-23 C403.3.2, Tables C403.3.2(8) and (9), VRF Equipment testing procedures WA State Energy Code-Commercial 2021
2024 24-22 C404.11, Pools and spas WA State Energy Code-Commercial 2021
2024 24-21 C403.4.1.7, C403.4.11.4 Demand responsive controls WA State Energy Code-Commercial 2021
2024 24-20 C403.3.2 HVAC equipment efficiency testing WA State Energy Code-Commercial 2021
2024 24-19 Chapter 11 Refrigeration systems in public corridors and lobbies International Mechanical Code 2021
2024 24-18 1101.1, 1109.3.2, 1109.4.2 Residential refrigeration systems International Mechanical Code 2021
2024 24-17 1109.2.5 Exterior refrigerant piping enclosure venting International Mechanical Code 2021
2024 24-16 1109.2.5 Refrigerant piping shaft International Mechanical Code 2021
2024 24-15 1109.2.5, 1109.3.2, 1109.4.2 Refrigerant piping shaft construction International Mechanical Code 2021
2024 24-14 1109.3.2, 1109.4.2 Refrigerant piping shaft ventilation International Mechanical Code 2021
2024 24-13 Chapter 15, Application of standards International Mechanical Code 2021
2024 24-12 Chapter 15. ASHRAE 15 and 34 International Mechanical Code 2021
2024 24-11 607.2.3, 607.6.2.1.2, Fire dampers and ERVs International Mechanical Code 2021
2024 24-10 C505.3, Change in occupancy WA State Energy Code-Commercial 2021
2024 24-09 R403.5.6, Water heater insulation WA State Energy Code-Residential 2021
2024 24-08 R302.3 Accessory Dwelling Units International Residential Code 2021
2024 24-07 2902 International Building Code 2021
2024 24-06 R406 Supplemental heating WA State Energy Code-Residential 2021
2024 24-05 R406 Supplemental heating WA State Energy Code-Residential 2021
2024 24-04 Table R402.1.3 / R503.1.1 Wall insulation in existing structure WA State Energy Code-Residential 2021
2024 24-03 R402.2.1 Ceilings with attic spaces WA State Energy Code-Residential 2021
2024 24-02 R406 Typos and Clarifications WA State Energy Code-Residential 2021
2024 24-01 IRC 330.7 Fire apparatus access roads and water supply for fire protection International Residential Code 2018
2023 23-09 IRC R324, IFC 1205 International Fire Code All Years
2023 23-08 R405, R406, C406 - Cited efficiency values WA State Energy Code-Commercial 2018, 2021
2023 23-08 R405, R406, C406 - Cited efficiency values WA State Energy Code-Residential 2018, 2021
2023 23-07 Definition, Residential building WA State Energy Code-Residential 2021
2023 23-06 2021 WUI Section 202 Definition International Wildland-Urban Interface Code 2021
2023 23-05 2018 IRC 330.7 Fire apparatus access roads and water supply for fire protection International Residential Code 2018
2023 23-04 R405, R406, C406 - Cited efficiency values: Supersedes 22-02 WA State Energy Code-Residential 2018, 2021
2023 23-03 429.1 and 429.2 International Building Code 2021
2023 23-02 403.4.4.1 ERVs in Group R-2 International Mechanical Code 2018
2023 23-01 C402.4.1 Window to wall ratio calculation WA State Energy Code-Commercial 2018
2022 22-03 104 Duties and Powers of the Code Official International Fire Code 2018
2022 22-02 R405, R406, C406 - Cited efficiency values WA State Energy Code-Residential 2018, 2021
2022 22-02 R405, R406, C406 - Cited efficiency values WA State Energy Code-Commercial 2018, 2021
2022 22-01 R402.2.5 / Table R402.1.3 Mass Walls WA State Energy Code-Residential 2018