Washington building code
Washington has adopted 2021 WAC 51-50 (Washington State Building Code) based on 2021 IBC (incl. Appendix E). The table below lists the governing edition for every discipline a plan check touches, followed by the Washington cities and counties that amend it locally.
- Current edition
- 2021 Washington State Building Code suite (WAC Title 51), statewide amendments, effective March 15, 2024
- Prior edition
- 2018 code suite with Washington State Amendments (effective February 1, 2021)
- Code authority
- Washington State Building Code Council (SBCC); electrical administered by Washington State Department of Labor & Industries (L&I)
Edition changeover: Projects with a complete application on or before 2024-03-15 may still be reviewed under the 2018 code suite with Washington State Amendments (effective February 1, 2021).
Adopted code by discipline
| Discipline | Adopted code | Local amendment |
|---|---|---|
| Building | 2021 WAC 51-50 (Washington State Building Code) based on 2021 IBC (incl. Appendix E) | n/a |
| Residential | 2021 WAC 51-51 (Washington State Residential Code) based on 2021 IRC | n/a |
| Existing buildings | 2021 2021 IEBC (adopted within WAC 51-50) based on 2021 IEBC | n/a |
| Fire | 2021 WAC 51-54A (Washington State Fire Code) based on 2021 IFC | n/a |
| Electrical | 2023 WAC 296-46B (Electrical Safety Standards, Administration, and Installation) based on 2023 NEC (NFPA 70) | n/a |
| Mechanical | 2021 WAC 51-52 (Washington State Mechanical Code) based on 2021 IMC | n/a |
| Plumbing | 2021 WAC 51-56 (Washington State Plumbing Code) based on 2021 UPC (IAPMO) | n/a |
| Energy | 2021 WSEC, Washington State Energy Code (WAC 51-11C Commercial, WAC 51-11R Residential) based on 2021 IECC (heavily amended state-specific code) | n/a |
| Accessibility | 2017 ICC A117.1-2017 + IBC Chapter 11 (WAC 51-50-005, pursuant to chapters 70.92 and 19.27 RCW) based on ICC A117.1-2017 | n/a |
| Fuel Gas | 2021 WAC 51-52 (within Washington State Mechanical Code) based on 2021 IFGC; NFPA 54/ANSI Z223.1-2021 and NFPA 58-2020 for LP-gas per RCW 19.27.031 | n/a |
Overlays that can apply
Mapped hazard and district overlays stack on top of the adopted code. These are the overlays recorded for Washington. They apply by parcel, not jurisdiction-wide, so confirm the parcel before assuming one is in play. Check CAL FIRE's fire hazard severity viewer and FEMA's flood map service.
- Seismic design category overlay
- Wildland-urban interface area
Sources
- https://app.leg.wa.gov/wac/default.aspx?cite=51
- https://app.leg.wa.gov/wac/default.aspx?cite=51-50&full=true
- https://app.leg.wa.gov/wac/default.aspx?cite=51-52&full=true
- https://sbcc.wa.gov/
- https://sbcc.wa.gov/state-codes-regulations-guidelines
- https://www.lni.wa.gov/licensing-permits/electrical/laws-rules-policies
- https://app.leg.wa.gov/rcw/default.aspx?cite=19.27.031
- https://app.leg.wa.gov/rcw/default.aspx?cite=19.27.060
- https://www.iccsafe.org/adoptions
Common questions
What building code does Washington use?
Washington uses 2021 WAC 51-50 (Washington State Building Code) based on 2021 IBC (incl. Appendix E). It is administered by the Washington State Building Code Council (SBCC); electrical administered by Washington State Department of Labor & Industries (L&I). The prior edition was 2018 code suite with Washington State Amendments (effective February 1, 2021).
Do cities in Washington amend the state code?
Local amendments are adopted by ordinance at the city or county level. Confirm with the building department that reviews your permit.
Which edition applies to a permit already in review in Washington?
Projects with a complete application on or before 2024-03-15 may still be reviewed under the 2018 code suite with Washington State Amendments (effective February 1, 2021).
Check a plan set against Washington code
Knowing the adopted edition is the easy half. Architechtura reads your drawings, resolves which of these provisions actually apply to the project, and returns the corrections a plan checker would write up, each one cited to the section it came from.
Your first check is free, no card required.
Compiled from published state and municipal adoption ordinances. Local governments amend their codes on their own schedule, and a pending ordinance can change what applies to your permit. Confirm the governing edition with the building department before you submit. This page is reference information, not a code determination.