Mercer Island hearing examines setback deviation and reasonable‑use exception for Baumann property

A Mercer Island hearing examiner on Sept. 26 heard testimony on two related land‑use requests that would allow Tim and Kathy Baumann to demolish a legally nonconforming 1,830‑square‑foot house and build a new single‑family residence on a lot largely encumbered by wetland and watercourse setbacks.

The applicants requested a front‑yard setback deviation that would reduce the standard 20‑foot requirement to 10 feet and a reasonable‑use exception (RUE) from critical‑area rules. Regan McClellan, an architect with McClellan Talone Architects, said those changes are necessary because wetland and watercourse buffers, steep‑slope constraints and an access easement cover essentially the entire buildable area.

"The critical areas and setbacks cover 90% of the site and 100% of the buildable area, making the site unbuildable without a zoning exception," McClellan said, describing the parcel as "odd shaped" and crossed by an access easement and buried piped watercourse. He said the piped watercourse is buried 8 to 13 feet below the surface and that exposing it would require an excavation too large for the lot.

Why this matters: the site sits adjacent to off‑site wetlands and a Type F watercourse whose buffers extend over the property. How the city balances protecting those critical areas against an owner’s ability to use land is the central question in RUE hearings; decisions establish whether the applicant can rebuild and, if so, what mitigation and conditions are required.

Applicant’s case and mitigation offer

McClellan and the applicants described an existing house built in 1953 that the architect and a builder’s inspection found to have significant foundation settlement and rot. The builder who surveyed the home, Jeffrey Wenzel of Mercer Builders, documented uneven floor levels and localized framing rot; McClellan said those conditions mean more than 40% of the exterior walls would need replacement if the owners attempted to remodel the structure and keep its legal nonconforming status.

The proposed new home would be a three‑story design with a smaller footprint to reduce disturbance, McClellan said. Key numeric details provided by the applicants and the project materials include: - Existing house: 1,830 sq. ft.; originally built 1953. - Proposed new home: 3,753 sq. ft. - Neighborhood average for eight surrounding homes: 3,975 sq. ft. - Proposed mitigation area: 2,937 sq. ft., equal to about 211% of the standard 1,393‑sq.‑ft. mitigation typically required for the increase in lot coverage. - Daylight basement area: about 500 sq. ft. - Code‑required parking for the proposed home: three cars; the project would add a three‑car garage where none now exists.

McClellan said the setback deviation would move the new building footprint farther from critical‑area source points, reduce intrusion into steep‑slope areas and allow off‑street parking. He also presented three alternatives the owners considered: a major, and by the applicant’s estimate costly, remodel (estimated $800,000–$1,000,000) that still would likely require coming into full compliance; selling the parcel at a reduced value; or abandoning the house until it could be condemned so the owners could pursue a later rebuilding attempt. McClellan characterized those options as economically impracticable.

Staff position and procedural issues

Molly McGuire, senior planner for the City of Mercer Island, summarized the staff report and said staff reviewed the proposal against the city’s critical‑areas and reasonable‑use standards. McGuire noted a SEPA (State Environmental Policy Act) determination of nonsignificance was issued Aug. 4, 2025, with no appeals, and that staff recommended approval with conditions. Among the recommended conditions is a requirement that a detailed mitigation plan be submitted and reviewed at building permit, demonstrating "equivalent or greater ecological function" for impacts to the watercourse and buffers (referencing Mercer Island City code wording in the staff report).

Both the applicant and staff acknowledged what will be required later in the process: a Critical Area Review at the building‑permit stage and detailed mitigation measures prepared by a qualified biologist.

Hearing examiner’s comments and next steps

Hearing Examiner Phil Walbrechts reiterated that by state law his decision must be based on evidence entered into the record at the hearing and asked whether any party objected to admitting the exhibits; he admitted exhibits 1 through 32, which include the staff report, project plans, a wetland and stream delineation, and comment letters. He expressed concern that the administrative record did not include a full impacts and mitigation assessment prepared by a qualified biologist and said he would have preferred to see that analysis come forward with the application.

"I kind of would have liked to seen a full critical area support," the examiner said, adding that such a study is important to determine whether impacts can be fully mitigated. McGuire and the applicant said a full Critical Area Review will be produced at the building‑permit stage; staff’s recommended condition requires the mitigation plan then.

The examiner said he expected to issue a written decision in the coming weeks and signaled that, based on the record and staff recommendation, approval with conditions was likely but that the decision must rest on the evidence in the record.

Public comment and participation

No members of the public registered to speak at the virtual hearing. The applicant team stated they had worked with city staff over nearly two years on the application.

What remains unresolved

The record at hearing lacked a full critical‑area impact/mitigation assessment from a biologist; the city and applicant intend that assessment to be completed during building‑permit review and as required by the staff‑recommended condition. The hearing examiner noted that absence as a material gap but did not close the record, instead reserving his decision to allow consideration of the submitted exhibits and testimony.

The hearing record will be the basis for the examiner’s written decision, which the examiner said he would issue within a few weeks.