Do I need parking for an ADU in Washington?
✓ Verified against code · August 19, 2026
It depends entirely on your city. HB 1337 only bars cities from requiring parking near major transit stops — beyond that, cities set their own rules, and most went further than the floor. Seattle, Tacoma, Redmond, and Olympia require zero off-street parking for ADUs citywide, no transit test needed. Others kept it conditional: Kent requires one space only beyond a half-mile transit walk, and Bellevue requires one space only for ADUs 1,000 sq ft or larger outside that same half-mile radius. Bothell and Shoreline went further still, repealing minimum parking for all housing, not just ADUs.
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?
- 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?
- Which WA cities have pre-approved ADU plans?
- 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.