Plan Commission backs ADU code changes to comply with state law, keeps 1,000‑sq‑ft unit cap

The Spokane Plan Commission unanimously recommended that City Council adopt code amendments to Spokane Municipal Code Chapter 17 that update local rules for accessory dwelling units to comply with House Bill 1337 and related state requirements.

Tim Thompson, who presented the ordinance changes, told the commission the amendments implement new state rules from House Bill 1337 (2023 legislative session) and related RCW provisions. "House Bill 1337 was adopted and codified in the RCW," Thompson said, summarizing mandated changes including a minimum allowance for two ADUs per lot, a 1,000‑square‑foot minimum allowed ADU size (the city implemented a 1,000‑square‑foot cap on ADU living area), removal of owner‑occupancy requirements (except for short‑term rentals), prohibitions on new CC&R bans on ADUs, limits on street improvement requirements, and caps on impact fees.

Thompson said the city also secured a Department of Commerce middle housing grant of $75,000 to support the code updates; the city received one third of that grant so far (approximately $18,750) and the ordinance is the final deliverable required to receive the remainder. In drafting the ordinance staff focused on four items where Spokane code did not align with the new state law, and those are addressed in the proposed amendments.

Key technical details explained by staff include: the living‑area limit for an ADU is 1,000 gross square feet; the code allows a building footprint up to 1,200 square feet to accommodate covered porches or covered entryways; two ADUs may be allowed on a single lot (combined footprint up to 2,400 square feet under the adopted approach); ADUs are exempt from certain street or alley improvement requirements; interior entry orientation restrictions were removed; and previous parking cleanup was performed. Thompson also noted an exception allowing an existing attic or basement area larger than 1,000 square feet to be converted without the cap applying.

Commissioners commented in support. One commissioner praised the city’s earlier ADU improvements and said the latest changes are largely technical updates to meet state law; another commissioner noted the visible increase in additional living units built after earlier code changes. There was brief discussion about whether ADUs are treated the same as additional dwelling units for open space requirements; Thompson said he did not recall a difference and suggested open space requirements are typically applied per dwelling unit, which would mean ADUs could be subject to the same standard.

After public testimony (none) a commissioner moved to recommend approval to City Council; a roll call vote recorded six ayes and the motion passed 6‑0. Thompson told commissioners the ordinance was scheduled for City Council first reading on June 2 and a council hearing likely on June 16.

The recommended changes align city code with state law and are framed as primarily technical and compliance updates; they do not themselves appropriate additional funds or change other unrelated land‑use regulations beyond those required by state statutes.