King County, WA Fence Regulations: Height Limits (2026)

Fences in unincorporated King County are governed primarily by the zoning code at K.C.C. Title 21A, with development standards in Chapter 21A.14 and density and dimension tables in Chapter 21A.12. King County's Department of Local Services - Permitting Division (DPER's successor) states that fences up to 6 feet in height may be built on or within property lines without a building permit; fences over 6 feet in height require a building permit and must meet the required setbacks for the zoning of the parcel. The state authority to adopt these zoning standards is RCW 36.70A (the Growth Management Act). Setback figures for taller fences come from the zone-specific tables in K.C.C. 21A.12.030 for residential (R) and rural (RA, A) zones and K.C.C. 21A.12.040 for forestry, mineral, commercial, and industrial zones. Where a property contains a critical area regulated under K.C.C. Chapter 21A.24 (wetlands, streams, fish-and-wildlife habitat, flood hazard areas, or geologically hazardous areas), a fence may need to be set back from the edge of the buffer or may require a critical-areas review even if it is 6 feet or shorter. Sight-distance triangles at street intersections and driveways are governed by the King County Road Design and Construction Standards; fences placed in those triangles must not block driver visibility regardless of height limit. Up to three strands of barbed wire are typically allowed atop a 6-foot fence in agricultural and rural-zoned parcels under K.C.C. 21A.14.220; barbed-wire and electrified fences in residential zones are restricted. Within incorporated cities, including Seattle, Bellevue, Kirkland, Redmond, Renton, Sammamish, Shoreline, Burien, Federal Way, Issaquah, and Kent, the city's own zoning code applies and front-yard limits are typically lower (often 3-4 feet).