U.S. code adoption

Washington — energy & appliance code adoption

Yes — effectively. This page summarizes electrical (NEC), appliance-listing (UL 858), fire-code, and energy-storage (UL 9540 / NFPA 855) code adoption for Washington, with primary sources.

Is UL 858 required in Washington?

Yes — effectively. Washington requires fixed household appliances to be listed by a Nationally Recognized Testing Laboratory (NRTL), and UL 858 is the de-facto listing standard a household electric range must meet.

Are NRTL-listed (UL / ETL / CSA) appliances required in Washington?

Yes. Washington's adopted code requires fixed electrical appliances to be listed by an NRTL (UL, ETL/Intertek, CSA, etc.) — NEC 110.3.

Which edition of the NEC does Washington use?

Washington has adopted the 2023 edition of the National Electrical Code (NEC).

Is UL 9540 required for residential energy storage in Washington?

Yes. Washington's adopted code requires UL 9540 listing for stationary energy storage systems (ESS) in dwellings. WA SBCC adopts WSFC; L&I handles electrical permitting; State Fire Marshal under WSP. UL 9540A required to exceed the 20 kWh residential threshold.

Is UL 9540A fire-propagation testing required in Washington?

Yes — effectively. Washington requires NRTL listing for energy storage systems, and UL 9540A is the controlling standard.

What is the residential energy-storage capacity limit in Washington?

Washington limits residential energy storage to 20 kWh per dwelling unit.

Which fire code does Washington enforce?

Washington enforces other.

Code adoption summary

NEC edition2023 NEC
Appliance listing (UL 858)Effectively required
NRTL listing requirementRequired
Fire codeother
UL 9540 (residential ESS)Required
UL 9540A propagation testEffectively required
Residential ESS cap20 kWh / dwelling
NFPA 855 edition2020

Local authorities in Washington

Sources

Data is illustrative. Verify any compliance decision against the cited primary sources and the NFPA NEC enforcement maps before relying on it.