Mirrormont Property Maintenance: Vacant Lot Maintenance Rules (2026)

Vacant or undeveloped lots in unincorporated King County are subject to general property maintenance standards and, in rural and wildland-urban interface areas, fire code requirements. Under KCC Title 23, vacant lots may not be used for accumulation of junk, debris, or inoperable vehicles. Overgrown vegetation that creates a fire hazard or impedes sight distance at road intersections is a violation of KCC 14.30 and, where applicable, KCC 17.04 (Fire Code). In Urban Growth Areas, vacant lots should be maintained with grass mowed and brush controlled; the county may issue notices to remove overgrown vegetation. In rural and wildland-urban interface zones (much of eastern King County near the Cascade foothills), the International Wildland-Urban Interface Code as adopted locally and Washington Department of Natural Resources fire rules require defensible space around structures, typically a 30-foot zone of reduced vegetation and a 100-foot outer zone of thinned fuels. Vacant lots abutting homes are expected to contribute to defensible space if the owner is the same. Dumping on vacant lots is a persistent issue, and owners are responsible for cleaning up debris on their property. Persistent dumping may qualify the property for King County Illegal Dumping Program assistance but does not relieve the owner of cleanup responsibility. In shoreline, wetland, or critical area parts of a vacant lot, KCC 21A.24 restricts vegetation clearing even by the owner.