WA · State directory
Washington ADU rules
Official accessory dwelling unit regulations for 9 jurisdictions in Washington, plus statewide law.
Not sure which city yet?
We have read the ordinances for 6 Washington cities and lined them up side by side: detached vs internal, size limits, owner occupancy, and approval process.
Statewide ADU law
Washington has state-level ADU legislation that applies across local jurisdictions. Local rules below may add requirements on top of state law.
Cities
Counties & regions
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