Planning commission prioritizes ADUs and sub‑area plans in housing action plan review

The Mountlake Terrace Planning Commission reviewed a draft housing action plan matrix on Sept. 22, 2025, with commissioners singling out accessory dwelling units and sub‑area planning as early priorities and asking staff to return with a fuller draft and implementation details.

Commissioners and staff spent the bulk of the meeting scrutinizing near‑term and midterm actions meant to implement the city’s comprehensive plan. Presenter Mackenzie told the commission the group’s focus that night was “to hear what the city’s already doing and identify the amount of effort that would be needed for each action,” and to hone the near‑ and midterm items that staff expect to implement first.

Why it matters: Commissioners said they want a clear work plan the next 12–36 months so limited staff and budget can be allocated to the highest‑impact steps. ADUs were repeatedly identified as a near‑term, high‑leverage option because state law recently streamlined ADU permitting and the local housing market can absorb smaller units faster than larger multifamily buildings.

Key points: Staff reviewed a range of actions grouped by timeframe and type. Near‑term regulatory steps included offering expedited permit review for homeowners who use preapproved ADU plans, amending permit review processes to accelerate affordable housing projects, updating mobile‑home park standards, and clarifying definitions for modular and alternative housing types. Mackenzie also presented a near‑term financial option enabled by state law: “consider offering a property tax exemption for ADUs rented to low income households below 60% AMI,” which would be an incentive for owners to rent at below‑market rates.

Commissioners debated how prescriptive the city should be about preapproved ADU plans. Some cautioned that preapproved designs can be cost‑intensive to establish and can produce mismatches with Mountlake Terrace’s varied lot and building stock; one staff example cited a set‑up cost of about $350,000 for a comparable program in another jurisdiction. Commissioners asked staff to explore a program design step and cost estimate rather than assuming immediate implementation.

There was broad agreement that finishing sub‑area plans should be a near‑term work‑plan priority. Chair Batista said the sub‑area work has been on the agenda for many years and “we should finish it,” and several commissioners endorsed pushing that item forward while also phasing in ADU‑focused actions.

Midterm proposals discussed included adopting targeted multifamily tax exemption (MFTE) programs (8‑ and 12‑year variants) in the gateway, neighborhood mixed‑use and town‑center zones, and considering density bonuses paired with income‑restricted units. Staff said the MFTE options were informed by fiscal analysis that will be summarized in the appendix of the full action plan.

Staff also highlighted cross‑cutting items: monitoring regulated and naturally occurring affordable housing at risk of redevelopment, strengthening tenant‑protection resources, producing educational materials on innovative building practices, and pursuing partnerships with community land trusts and Snohomish County to improve access to HOME, CDBG and other funds.

Process and capacity limits: Commissioners repeatedly raised capacity constraints. Staff agreed that sequencing many of these actions depends on staffing and resources; level‑of‑effort estimates will be added to the full draft. Several procedural options were discussed to expedite projects without overwhelming staff, including reducing procedure types for qualifying affordable projects rather than simply jumping one applicant to the front of the queue.

Votes at a glance: During miscellaneous business the commission approved a motion to excuse Commissioner Stinson from the Nov. 10, 2025 meeting (motion made and seconded; chair called for aye and the motion carried).

What’s next: Staff said they will return with a full housing action plan draft on Oct. 27 that includes level‑of‑effort estimates and the fiscal appendix; the plan will be revised based on commission feedback, followed by a public hearing and presentation to the city council in early December. Commissioners asked staff to replace repeated tentative language (‘consider’) with firmer action verbs (’adopt’, ’offer’, ’implement’) where appropriate.

The commission adjourned the housing discussion to move to the director’s report and other business.