Which WA cities have pre-approved ADU plans?
✓ Verified against code · August 19, 2026
It varies — some cities have active programs, others are still building them. Kirkland runs the most developed program in our data: an active gallery of vetted DADU designs with a capped $1,000 designer royalty and expedited review. Renton's PRADU program offers roughly eight free pre-engineered plans with waived fees, estimated at $40,000 in savings. Olympia offers six pre-approved stock plans from 480 to 1,000 sq ft. Seattle's ADUniverse program permits pre-approved designs in roughly 2–6 weeks. Bellevue and Lynnwood both have programs in development but not yet live — check before assuming a plan gallery exists in your city.
Citation: varies by city — see city pages
How current is this?
Washington’s ADU rules run under HB 1337 (2023). HB 1337 required every Washington city over 25,000 people to allow two ADUs per residential lot, drop owner-occupancy requirements, cap size limits no lower than 1,000 sq ft, cap height limits no lower than 24 ft, and stop requiring parking near major transit — with compliance due June 30, 2025 for larger cities. We verified this answer against primary sources on August 19, 2026, and every change we catch is logged in the changelog.
More Washington ADU questions
- How many ADUs can I build in Washington?
- What is HB 1337?
- Do I need parking for an ADU in Washington?
- Can cities require me to live on the property?
- How big can an ADU be in Washington?
- Can I sell an ADU separately in Washington?
- When did WA ADU rules change?
- How tall can an ADU be in Washington?
- How close to my property line can an ADU be built?
- Will I have to pay impact fees on an ADU in Washington?
- How long does it take to get an ADU permit in Washington?
Not legal advice — local ordinances can go further than the state floor. The citation above points at the governing statute; check your city’s code for the specifics.