Washington Zoning & Land Use Guide
Last updated: Verified:
Comprehensive guide to Washington zoning laws, building codes, and land use regulations.
Key Facts
- Building Code: WA State Building Code (based on 2021 IBC)
- State ADU Law: Yes — ADU-friendly
- ADU Details: HB 1337 (2023) requires cities and counties planning under the GMA to allow at least two ADUs per single-family lot.
Official Sources
Cities in Washington
Auburn
Pop. 87,256
ADU: Allowed
Bellevue
Pop. 151,854
ADU: Allowed
Bellingham
Pop. 91,482
ADU: Allowed
Everett
Pop. 110,629
ADU: Allowed
Federal Way
Pop. 101,030
ADU: Allowed
Kennewick
Pop. 83,921
ADU: Allowed
Kent
Pop. 136,588
ADU: Allowed
Kirkland
Pop. 92,175
ADU: Allowed
Lakewood
Pop. 63,612
ADU: Allowed
Olympia
Pop. 55,605
ADU: Allowed
Pasco
Pop. 77,108
ADU: Allowed
Redmond
Pop. 73,256
ADU: Allowed
Renton
Pop. 106,785
ADU: Allowed
Richland
Pop. 60,560
ADU: Allowed
Sammamish
Pop. 67,455
ADU: Allowed
Seattle
Pop. 737,015
ADU: Allowed
Spokane
Pop. 228,989
ADU: Allowed
Spokane Valley
Pop. 102,976
ADU: Allowed
Tacoma
Pop. 219,346
ADU: Allowed
Vancouver
Pop. 190,915
ADU: Allowed
Disclaimer: The information on this website is provided for general informational purposes only and does not constitute legal, financial, or professional advice. Always verify current requirements with your local planning department.