Bill > SB5357

This bill establishes limitations on detached accessory dwelling units (ADUs) outside of urban growth areas in Washington state. The key provisions include: (1) allowing counties to permit detached ADUs outside urban growth areas, but limiting each parcel to one detached ADU; (2) requiring detached ADUs to meet water supply and sewage/septic system requirements; (3) capping the size of detached ADUs at 1,296 square feet; and (4) mandating that detached ADUs be designed to match the primary dwelling's exterior materials, roof form, and proportions. The bill also clarifies that this does not affect existing county ordinances authorizing ADUs or exclude other means of authorizing ADUs consistent with the act.