Kent requires a building permit for retaining walls over 4 feet tall measured from footing to top. Walls supporting surcharges or on geologically hazardous slopes need a permit at any height under WAC 51-16.
Kent adopts the Washington State Building Code exemption in WAC 51-16-080, which states that retaining walls not over 4 feet in height measured from the bottom of the footing to the top of the wall do not require a permit, provided the wall does not support a surcharge such as a driveway, structure, or sloped soil. Walls over 4 feet, walls supporting any surcharge, and walls impounding Class I, II, or III-A liquids all require a permit. Kent sits on the Green River Valley floodplain and adjacent hillsides of West Hill and East Hill, where geologically hazardous areas trigger additional review under KCC 11.06 (Critical Areas). In those zones, even a short retaining wall may need geotechnical engineering review and a critical areas permit. Rockeries built with stacked rock and no mortar are treated like retaining walls for the 4-foot threshold. Submit plans through the Kent Permit Center. Retaining walls at or near the property line must also comply with the fence rules of KCC 15.08.
Unpermitted retaining walls face stop-work orders and double permit fees. Failed retaining walls can trigger property damage liability and mandatory remediation.
Kent, WA
Kent decibel limits follow WAC 173-60 and KCC 8.05 using EDNA zones. Residential receiving limit is 55 dBA day and 45 dBA night. Commercial sources are cappe...
Kent, WA
Kent industrial sources are capped at 70 dBA day and 65 dBA night at another industrial property, but only 60 dBA day and 50 dBA night when received at a res...
Kent, WA
Commercial trucks over 10,000 pounds GVWR generally cannot park on Kent residential streets except for active loading. Warehouse districts and truck routes h...
Kent, WA
Kent follows Washington State Building Code EV-ready requirements for new multifamily and commercial buildings. Public chargers exist at Kent Station and sev...
Kent, WA
Kent driveway aprons require Public Works approval under KCC Title 6. New or widened driveways need a right-of-way construction permit, and vehicles must not...
Kent, WA
Kent follows RCW 16.30 which prohibits private possession of dangerous wild animals including big cats, bears, wolves, primates, elephants, and venomous rept...
Side-by-side rule comparisons with other cities in King County.
See how other cities in King County handle retaining walls.
See how Kent's retaining walls rules stack up against other locations.
Help us keep this page accurate. If you notice an error or outdated information, let us know.