Anacortes planning commission reviews draft ADU code to align with state law

The Anacortes Planning Commission reviewed draft amendments to the city’s accessory dwelling unit (ADU) regulations during a planning commission meeting, where staff said the changes respond to state law enacted in House Bill 1337 and to recent updates to the municipal code.

The draft would require the city to allow at least two ADUs on lots in zones that permit single-family housing, raise the city’s existing maximum ADU gross floor area to 1,000 square feet to comply with state limits, set a 25-foot maximum height for detached ADUs, and revise parking and setback standards. Planning staff said the revisions will be folded into a larger package of housing-related zoning changes and returned to the commission for a formal recommendation.

Libby Grage, planning manager in the Planning, Community and Economic Development Department, briefed commissioners on the history and the proposed code language. "Accessory dwelling units have been addressed in the Anacortes Municipal Code since 02/2008," she said, and summarized the statute she was citing: "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 walked commissioners through proposed new definitions, height and setback rules, parking changes, and exceptions tied to sewer service and critical-area protections.

Grage told the commission the city’s existing ADU code has been revised several times (2016, 2019 and 2024) and described current rules: one ADU per single-family lot, a 900-square-foot local maximum until revised, parking requirements that currently total three off-street spaces (two for the principal single-family unit plus one for the ADU), and a prior requirement prohibiting separate ownership of an ADU. She said HB 1337 requires jurisdictions to allow multiple ADU configurations — attached, detached, conversions and combinations — and to remove owner-occupancy mandates where they still exist.

Commissioners focused on specifics. Grage said the draft would allow up to two ADUs on any lot that meets the minimum lot size for the principal unit and described configurations that could satisfy that allowance: "one attached and one detached ADU, two attached ADUs or two detached ADUs," including two ADUs inside a single detached structure. On height, she explained that the proposed city standard sets detached ADUs at a 25-foot maximum, noting the statute prevents cities from establishing maximum heights lower than 24 feet. She described the prior roof-pitch/massing rule (for example, a <6:12 pitch limiting height to 20 feet) and the planning staff rationale for removing the daylight-plane standard because it was hard for applicants to apply and would conflict with the state requirements.

Grage also summarized parking and lot coverage implications: the draft requires one off-street parking space per ADU, and where paved on-street parking meeting standards abuts the lot that on-street space may satisfy an ADU parking requirement. She said existing maximum lot coverage and minimum landscaping requirements for each zone would still apply, which could limit construction of multiple detached ADUs on lots already near lot-coverage caps.

Commissioners raised implementation questions. Commissioner McCombs asked whether two detached ADUs would be blocked on lots already at maximum lot coverage; Grage confirmed that lot-coverage limits could prevent two detached ADUs. Commissioner Mills asked whether HOAs could block ADUs; Grage said the city enforces only city code and that private covenants are a private matter between an HOA and a property owner. Commissioner Currier requested that staff highlight any elements in the draft that go beyond what the state requires; Grage agreed to do so as the draft is refined.

The commission did not take a formal vote on the ADU amendments. Grage said staff will integrate the proposed ADU language into the larger comprehensive-plan and development-regulations update and return that consolidated package to the commission at a later meeting.

Background and next steps: Grage said HB 1337’s intent is to ease barriers to ADU construction to help address housing affordability; she noted Anacortes’s entire city lies within the urban growth area cited by statute, so the state ADU rules would apply citywide. The draft keeps other local controls in place where state law allows — for example, ADUs may still be subject to building, environmental and public-health permitting, and the city’s prohibition on short-term rentals in residential and commercial areas was not removed by the statute and remains in effect.

The commission asked staff for clarifications on a few technical points — such as how alley access and garage orientations affect required alley setbacks, how minimum lot-size rules interact with two-ADU configurations, and whether transit-based parking reductions apply in Anacortes — and staff noted some of those elements either are not applicable locally or will be clarified in the consolidated draft. Staff expects to return a combined package of housing-related amendments that includes the ADU language for formal recommendation and public hearing.