Anacortes planning staff outlines draft ADU code changes to meet new state law

Libby Grage, planning manager in Anacortes’ Planning, Community and Economic Development department, presented draft amendments to the city’s accessory dwelling unit regulations and explained how the changes respond to recent Washington state legislation.

Grage said the city has addressed accessory dwelling units in the Anacortes Municipal Code since February 2008 and that the code has been revised several times, most recently in 2024. "Accessory dwelling units have been addressed in the Anacortes Municipal Code since 02/2008," she said.

The proposed draft updates reflect House Bill 1337 (HB 1337), which Grage said requires jurisdictions to allow at least two ADUs on lots in zones that permit single-family residences and to allow a range of configurations (attached, detached, conversions or combinations). "The city or county may not establish a maximum gross floor area requirement for accessory dwelling units that is less than 1,000 square feet," Grage read from the statute during the presentation.

Key specifics in the draft presented to the commission include: - Permit at least two ADUs on any lot in zones that allow single-family housing; configurations may include one attached and one detached ADU, two attached ADUs, or two detached ADUs (which may be in one or two detached structures). - Increase the city’s current maximum ADU gross floor area to 1,000 square feet to align with state law language that prevents jurisdictions from setting a lower maximum. - Set the maximum height for detached ADUs at 25 feet (the presenter noted state law prohibits a maximum lower than 24 feet). - Remove the city’s existing 45-degree daylight-plane massing setback for ADUs (staff said the requirement was difficult for applicants to apply and that state law limits imposing massing standards that differ from those applied to principal units). - Maintain that ADUs must meet the lot’s principal-unit minimum lot-size requirement and comply with the zone’s maximum lot coverage and minimum landscaped-area requirements. - Require one off-street parking space per ADU; where paved on-street parking abuts the lot and meets standards, that space may count toward the ADU parking requirement. The city’s current practice of counting three total parking spaces for a single-family dwelling plus one ADU was described as being refined by the state rules. - Prohibit ADUs on lots not served by public sewer in the city.

Commissioners asked several clarifying questions. Commissioner McCombs pressed whether lot coverage limits could prevent two ADUs where a principal structure already reaches the zone’s maximum lot coverage; staff confirmed existing coverage requirements could effectively limit the practical ability to add two ADUs on some lots. On HOA rules, staff said permitting under city code would not override private covenants: enforcement of HOA restrictions would be a private matter between property owners and their HOA.

Grage noted the draft language includes some staff clarifications beyond the statutory text (for example, clarifying that a breezeway connection should not be treated as creating an "attached accessory dwelling unit" for purposes of height allowances) to avoid what she described as attempts in the past to use marginal connections to circumvent massing limits. "We chose to put this in to avoid that circumstance in the past," she said.

The commission did not take action; Grage said the ADU revisions will be incorporated into a larger package of housing-related code amendments for later review and recommendation. She also flagged deadlines for jurisdictions to adopt rules consistent with HB 1337, noting the statutory timeline has shifted during 2024–2025 and commissioners will see the ADU language again when staff integrates it into the complete update.

Ending: Staff will fold the ADU draft amendments into the broader comprehensive plan and development regulations update for future review and formal recommendation; no ordinance or vote was taken at the meeting.