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 conditions, including limitations on the number of units per parcel, compliance with water supply and sewage system requirements, and restrictions on size and location relative to the principal dwelling. The bill mandates that the gross floor area of the ADU cannot exceed 1,296 square feet and must utilize the same driveway as the primary unit. Additionally, if the ADU is used as a short-term rental, the primary unit must be owner-occupied, and water withdrawals must be metered.

Counties are required to track and report the number of ADU permits and their use as short-term rentals, updating their comprehensive land use plans accordingly. The bill also clarifies that existing county ordinances regarding accessory dwelling units remain valid and that other methods of authorizing such units are not excluded, provided they align with the new regulations. The definitions of terms related to accessory dwelling units are also amended to include the new provisions established by this act.

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