Accessory Structures in Kirkland, WA (2026)
4 verified accessory structures rules for Kirkland, Washington, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Kirkland allows up to two accessory dwelling units per single-family lot, attached or detached, each capped at 1,200 square feet, permitted through the Planning and Building Department with a recorded covenant and reduced parking near transit.
Kirkland Accessory Dwelling Unit Zoning Rules
Some RestrictionsKirkland Zoning Code KZC 115.07 Accessory Dwelling Units
Two Accessory Dwelling Units (ADUs), including either one attached ADU and one detached ADU, or two of either type, are permitted per single-family dwelling; provided, that an Accessory Dwelling Unit shall not be considered a "dwelling unit" in the context of special regulations in Chapters 15 through 56 KZC which limit the number of Detached Dwelling Units on each lot to one... 4. Size. The sq...
ADU Impact Fees
Kirkland caps the transportation impact fee on a new accessory dwelling unit at fifty percent of the fee that would apply to the principal house on the same lot. The cap, set by KMC 27.04.030(m) to comply with the state ADU statute, applies once an ADU exceeds 800 square feet, the point where the city's separate small-ADU exemption stops covering it.
Kirkland ADU Impact Fee Cap
Some RestrictionsKirkland Municipal Code 27.04.030(m)
To ensure compliance with RCW 36.70A.681(1)(a), the impact fee assessed on the construction of an accessory dwelling unit regulated in Chapter 115 KZC will not be greater than fifty percent of the impact fee that would be imposed on the principal unit.
Shed & Carport Rules
Kirkland caps detached accessory structures like sheds, garages and barns at 1,200 square feet, plus 10 percent of any lot area over 7,200 square feet, and limits their height under KZC 115.08. A shed stays permit-exempt under KMC 21.06.215(1)(A) only if it's 200 square feet or less, 120 for IBC structures, and no taller than 12 feet.
Kirkland Shed and Accessory Structure Rules
Some RestrictionsKZC 115.08 and KMC 21.06.215(1)(A)(i)
115.08 Accessory Structure (Detached Dwelling Unit Uses Only). Structures to be used as a tool shed, greenhouse, private garage, barn or similar use are permitted. The total size of all such structures may not exceed the gross floor area of 1,200 square feet plus 10 percent of the lot area that exceeds 7,200 square feet. ... The height (roof peak elevation) of an accessory structure in all resi...
Garage Conversions
Converting a detached garage into an accessory dwelling unit in Kirkland is exempt from the zone's current setback and lot coverage rules under KZC 115.07(6), so long as the conversion doesn't increase any existing nonconformity. The resulting ADU is capped at 1,200 square feet of gross floor area and must meet applicable building and fire code standards.
Kirkland Garage Conversion to ADU Rules
Some RestrictionsKZC 115.07(6) (Accessory Dwelling Units - Conversion of Existing Structures)
4. Size. The square footage of the ADU shall not exceed 1,200 square feet of gross floor area. ... 6. Conversion of Existing Structures. Permitted conversion of existing structures, including detached garages, to ADUs shall be exempt from current zoning setback and lot coverage requirements, on the condition that any existing nonconformities are not increased.
Looking for King County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Kirkland city rules.
Accessory Structures in King County →