The bill amends RCW 36.70A.536 to facilitate the development of middle housing in unincorporated areas of Washington State. It allows counties that are required or choose to plan under RCW 36.70A.040 to authorize middle housing types on parcels that permit single-family residences. The bill specifies that no more than four residential units may be authorized per lot in both limited areas of more intensive rural development and designated urban growth areas. Additionally, it mandates that development regulations for middle housing cannot be more restrictive than those for detached single-family residences and must include provisions for necessary infrastructure, such as publicly owned sanitary sewer systems.

Key insertions in the bill include definitions for "rural county" and "large on-site sewage system," as well as requirements for middle housing to be served by water and sewer services in designated urban growth areas. The bill also clarifies that middle housing in rural counties must be served by a publicly owned sanitary sewer system or a large on-site sewage system. Overall, the legislation aims to promote the construction of middle housing while ensuring that it meets certain infrastructure and regulatory standards.

Statutes affected:
Original bill: 36.70A.536
Substitute bill: 36.70A.536
Bill as passed Legislature: 36.70A.536
Session law: 36.70A.536