ADU Builders in Washington
Washington's HB 1337 created sweeping ADU rights across most of the state.
Permit timeline
90 days
Max size
1000 sqft
Owner-occupancy
Not required
Rentals
Allowed
Cities in Washington
Washington ADU Law Summary
Washington passed HB 1337 in 2023, requiring cities to allow at least two ADUs per lot in most residential zones. Owner-occupancy requirements are prohibited.