Planning Commission approves design review and front‑setback variance for 309 Tamalpais Avenue, 4–1

The Mill Valley Planning Commission on March 24 approved a design‑review application and a variance that would allow part of the existing nonconforming front wall at 309 Tamalpais Avenue to remain as the property is rebuilt and enlarged.

Chair Kevin Skiles (Chair) said the application, which proposes a two‑story addition and substantial remodel to create about 4,600 square feet of living space on an approximately 33,000‑square‑foot lot, “fits the site” and that reusing existing foundation elements would reduce off‑site impacts. Staff planner Steven Ross recommended finding the project categorically exempt under the California Environmental Quality Act (CEQA) — citing CEQA Guidelines §§15301 and 15303 — and recommended approval with the findings and conditions in the record.

Architect Joe Maguire, presenting for owners Paul Gaetani and Jennifer Krasner, explained that the project would convert a lower‑level garage to living area, add roughly 900 square feet on the upper story, build a new detached two‑car garage and add a pool and patio. Maguire said the proposal requires removing two small oak trees and about 200 cubic yards of grading, with an estimated 127 cubic yards of imported fill. He also said the Southern Marin Fire Department reviewed and accepted the site’s 150‑foot hose‑reach plan and a staging area in the driveway.

Commissioners focused much of their discussion on two questions: whether the scope of demolition crossed the municipal “voluntary demolition” threshold (staff calculated demolition at about 78% of the roof and 67% of horizontal wall area, which triggers full compliance with development standards), and whether granting a variance would be fair and consistent compared with recent cases. Commissioner Macros opposed the variance on fairness grounds, saying the commission previously denied similar relief to others; Commissioner Goff and others countered that the project is largely hidden from the street, reuses existing foundation, and has neighbor support.

The commission’s motion — moved by Commissioner Goff and seconded by Commissioner Gasparick — proposed finding the project CEQA exempt and approving the design review and variance based on testimony, the record, Exhibit A findings and conditions in Exhibit B. Roll call vote: Seringle — yes; Goff — yes; Macros — no; Gasparick — yes; Chair Skiles — yes. The motion passed 4–1. Staff noted an appeal period of 10 calendar days following the decision and an appeal fee of $1,112.

Key details recorded in the hearing record include the 99 square feet of existing encroachment the applicants seek to retain, the project’s proposed total area (about 4,600 sq ft), removal of two oak trees (7" and 9" diameter), estimated 200 cubic yards of site grading with 127 cubic yards to be imported, and the applicant’s statement that the proposed materials will include compliant cedar‑style siding, metal‑clad windows, and photovoltaic panels.

The commission’s approval included the conditions in Exhibit B; staff and the applicant said minor plan adjustments (e.g., clarifying roof geometry and final fill calculations) could be resolved before building permits are issued. The commission closed the matter with the formal vote and a reminder about the appeal deadline.