Mercer Island planning commission declines most 2026 code-change proposals, splits on ADU and ceiling-height items

The Mercer Island Planning Commission voted on a set of nine proposed code and plan amendments on Oct. 22, 2025, and recommended against docketing most of the proposals for the 2026 work plan. Commissioners cited staff workload, outstanding state-mandated updates and potential conflicts with the city’s comprehensive plan in reaching their decisions.

Senior planner Molly Maguire told the commission that the annual docket review is the step that yields a recommendation to the city council and that proposed amendments must meet a set of criteria, including availability of staff resources and consistency with the comprehensive plan. "First, the planning commission will conduct a preliminary review of the proposed items and, make a recommendation to the city council," Maguire said during the staff presentation.

The nine proposals included a rezoning request for the former Tolles parcel, limits on use of residential lots by adjacent commercial properties, changes to reclassification/rezoning criteria, a clarification of parking rules in commercial zones, changes to how gross floor area (GFA) counts higher ceilings and exterior covered decks, a waterfront garage setback change, a cap on GFA incentives for accessory dwelling units (ADUs) on larger lots, and a reduction in the square-foot threshold that triggers a two-space parking requirement.

Commissioners considered each amendment individually. The commission voted to recommend that city council not docket amendments 25-1, 25-2, 25-3, 25-4, 25-6, 25-7 and 25-9. Two motions to docket technical changes failed: amendment 25-5 (reduce the ceiling height counted as bonus GFA from 12 feet to 10 feet) failed on a 4–1 vote, and amendment 25-8 (limit ADU GFA incentives to lots 8,400 square feet or smaller) failed on a 3–2 vote. After the item-by-item votes, the commission unanimously authorized staff to prepare the recommendation to the city council on the final docket.

Votes at a glance:

- 25-1 (rezoning Tolles parcel to park/public institution): motion to not docket carried 5–0. - 25-2 (restrict commercial properties from using adjacent residential lots for commercial purposes): motion to not docket carried 4–1. - 25-3 (prohibit certain nonresidential reclassifications into single-family zones): motion to not docket carried 5–0. - 25-4 (clarify parking standards and remove some parking reduction options in CO and B zones): motion to not docket carried 4–1. - 25-5 (count lower ceiling threshold in GFA calculation): motion to docket failed 1–4. - 25-6 (include exterior covered decks in GFA): motion to not docket carried 4–1. - 25-7 (eliminate the ability to build garages/carports within 10 feet of the property line on steep waterfront lots): motion to not docket carried 4–1. - 25-8 (limit ADU GFA incentives to lots 8,400 sq ft or smaller): motion to docket failed 2–3. - 25-9 (reduce threshold for requiring two parking spaces from 3,000 to 2,000 sq ft): motion to not docket carried 4–1.

Why it matters: the docket controls which code and plan amendments the city will study in depth next year. Staff warned the commission that several interim ordinances and state-mandated updates (including the Shoreline Master Program periodic review and compliance tasks tied to a Growth Management Hearings Board order) require staff time, which limits capacity to pursue new docket items. That timing influenced commissioners who said new items added now may not be reviewed until 2029 or later unless prioritized.

What’s next: staff will prepare the commission’s recommendation for the city council. The commission also announced a public hearing on Nov. 19 for a separate rezone of city hall and public-works parcels.