Kent, WA Accessory Structures: ADU Rules (2026)

350 was substantially rewritten by Ordinance 4464 in 2023 and amended again by Ordinance 4517 in 2025 to expand ADU capacity citywide. A lot may now have two ADUs in any combination: one attached and one detached, two attached, or two detached. An ADU may generally be sited anywhere on the lot that meets the district's setbacks, but a detached ADU in the rear half of the lot can be built to within two feet of the side and rear lot lines, and may even sit at a lot line abutting a public alley unless that alley is routinely plowed for snow.

The planning director can grant siting modifications where lot shape or existing structures make strict compliance infeasible. Detached ADUs are capped at 24 feet in height, with chimneys, antennas and railings allowed to extend up to four feet above that. 170 definition, and excludes areas with less than seven feet of ceiling height and up to 200 square feet of covered decks or porches; square footage cannot be transferred between two ADUs on the same lot. Metal, aluminum and fiberglass siding are prohibited. 170. A completed permit application is required for every ADU, with application requirements set by the economic and community development department, and an owner-occupancy covenant is no longer required; existing recorded covenants can be released by the planning director at the applicant's expense. An ADU may even be converted from an existing nonconforming garage or accessory structure without curing its existing setback or lot coverage violations.