The bill establishes regulations for detached accessory dwelling units (ADUs) outside urban growth areas in Washington State. It allows counties to permit these units under specific limitations, including restrictions on the number of units per parcel, compliance with water supply and sewage system requirements, and size limitations not exceeding 1,296 square feet. Additionally, the bill mandates that the ADU must be located on the same acre as the primary dwelling and utilize the same driveway, while also ensuring that the site does not encroach on designated agricultural or forestland. If the primary dwelling was built after the bill's effective date, the application for an ADU must be denied.

Furthermore, the bill amends existing definitions in RCW 36.70A.696 to include the new regulations for detached accessory dwelling units. It clarifies terms such as "detached accessory dwelling unit" and "short-term rental," and emphasizes that counties may adopt development regulations similar to those in effect as of January 1, 2024, for counties with populations exceeding 2,000,000. The new section added to the law is cumulative and does not affect existing ordinances or exclude other means of authorizing accessory dwelling units in urban or rural areas.

Statutes affected:
Original Bill: 36.70A.696
Substitute Bill: 36.70A.696