Seattle, WA Fence Regulations: Neighbor Fence Rules (2026)

Unincorporated King County does not enforce neighbor cost-sharing for boundary fences. Washington has no general statute like California Civil Code 841 compelling adjoining owners to split the cost of a division fence outside of livestock contexts under RCW 16.60. Fence disputes between neighbors are civil matters handled in district or superior court, not by county Code Enforcement. A fence must be built entirely on the owner side of the recorded property line unless both neighbors sign and record a written agreement placing it on the boundary. Encroaching fences can lead to adverse possession claims after 10 years of open, notorious, and continuous use under RCW 7.28.050. It is customary but not legally required in Washington to face the finished side of a fence toward the neighbor. Spite fences (erected solely to annoy a neighbor) can be actionable as a private nuisance. King County Code Enforcement will respond to height, permit, and critical-area violations, but will not mediate aesthetic or cost disputes between neighbors.