Washington — Code Adoption Summary
Adoption model: Statewide-mandatory (WA State Building Code Council); electrical via L&I. Aggressive energy code. Seattle heavily amends.
Last verified: 2026-07-03
Confidence: verified
Primary sources: WA SBCC — https://sbcc.wa.gov · L&I Electrical — https://www.lni.wa.gov/licensing-permits/electrical
Statewide adopted codes — current (2026; 2021-based)
| Code family | Adopted edition | Notes | Source |
|---|
| Building | 2021 IBC (WA amendments) | 2026 update in rulemaking (adoption targeted ~2026-08/09) | sbcc.wa.gov |
| Residential | 2021 IRC (WA) | | " |
| Electrical (NEC) | NEC 2023 | L&I; NEC 2026 replaces 2023 on 2026-12-31 | lni.wa.gov |
| Mechanical | 2021 IMC (WA) | | sbcc.wa.gov |
| Plumbing | UPC 2021 (Uniform Plumbing Code) | WA = UPC | sbcc.wa.gov |
| Energy | Washington State Energy Code (WSEC) 2021 (eff. 2024-03-15) — among strictest in US | commercial + residential | sbcc.wa.gov |
| Fire | 2021 IFC (WA) | | " |
Solar PV / ESS / EV
| Item | Status |
|---|
| NEC solar (690/705/706) | via NEC 2023 (→2026 on 2026-12-31) |
| EV / energy | WSEC 2021 EV-ready + electrification-forward |
Adoption model & precedence
- SBCC codes are statewide minimum; L&I administers electrical statewide (state electrical inspection except in cities with their own certified electrical program, e.g., Seattle, Tacoma, Spokane).
- AHJ = local building dept (building) + L&I or city electrical program (electrical).
Major cities / counties
| Jurisdiction | County | Notes | Building dept. |
|---|
| Seattle | King | Own amendments — Seattle Building Code, Seattle Energy Code (more restrictive), own electrical program | seattle.gov/sdci |
| Spokane | Spokane | WA codes + city electrical | spokanecity.org |
| Tacoma | Pierce | WA codes + city electrical | tacomapermits.org |
| Bellevue | King | WA codes | bellevuewa.gov |
AHJ fallback (when local adoption is unverified)
- State baseline: 2021 IBC/IMC, NEC 2023, UPC 2021, WSEC 2021.
- Action: in Seattle/Tacoma/Spokane confirm city amendments + city electrical program; confirm NEC 2023 vs 2026 by permit date (2026-12-31 switch).
Change log
- 2026-07-03 — created; verified NEC 2023 (→2026 on 2026-12-31), UPC 2021, WSEC 2021 (eff. 2024-03-15), 2021 IBC (2026 update pending).
