King County, WA Fire Regulations: Wildfire Zones (2026)

King County has adopted the 2021 International Wildland Urban Interface Code (IWUIC) via KCC Title 17 and the Washington State Building Code. The Washington Department of Natural Resources (WA DNR) maps wildfire hazard zones, with the eastern foothills, Snoqualmie River valley, Skykomish Valley, Vashon Island wildland areas, and the upper Cascades portions of unincorporated King County classified as moderate to high hazard. New construction and major remodels in designated WUI areas must use ignition-resistant exterior materials (Class A roofing, noncombustible or ignition-resistant siding, enclosed eaves, and ember-resistant vents meeting ASTM E2886). Defensible space is required: Zone 1 (0 to 5 feet) should be noncombustible; Zone 2 (5 to 30 feet) should be lean, clean, and green with reduced fuel loads; and Zone 3 (30 to 100 feet) should have thinned timber and removed ladder fuels. Burn bans are issued seasonally by Puget Sound Clean Air Agency and King County Fire Marshal (206-296-6533). Eastside Fire and Rescue, Mountain View Fire, Vashon Island Fire and Rescue, and other districts enforce local standards.