Committee reviews ADU compliance bill to align Seattle code with state law; follow-up on FAR and HB 1110 reconciliation expected

The committee discussed a compliance ordinance to implement provisions of state House Bill 1337 for accessory dwelling units (ADUs). SDCI staff said Seattle’s existing ADU rules already conform to many state requirements but the bill makes several clarifications and changes, including: allowing up to two ADUs per lot in all zones where residential use is permitted, normalizing the ADU maximum gross floor area to 1,000 square feet across zones (the low‑rise ADU limit had been 650 square feet), aligning conversion provisions for nonconforming structures across zones, clarifying street‑improvement rules for ADUs and harmonizing development and design standards (setbacks, entry door rules) across applicable residential zones.

SDCI staff noted the ordinance is intended to be a focused compliance measure and not to fully reconcile House Bill 1110 (the middle housing bill), which raises separate floor‑area and density questions; staff said a stepwise approach would leave broader FAR and lot‑coverage reconciliations to the HB 1110 work stream. Councilmember Moore asked specifically about floor‑area ratio (FAR) limits and whether ADUs would be affected by the HB 1110 interim legislation; staff said ADUs are currently exempt from FAR limits and the compliance ordinance does not reduce ADU FAR availability but acknowledged that reconciliation with HB 1110 will be needed. Staff recommended an effective date of June 30, 2025 — the state compliance deadline — and said SDCI would need a brief window to train staff and implement changes.

Committee members expressed general support and asked staff to return with reconciliations between HB 1337 compliance and HB 1110 interim legislation. No vote was taken on the ADU compliance ordinance at this meeting; staff will return with additional materials about how ADUs interact with the city’s HB 1110 implementation.