Planning Commission approves ADU at 176 Oak Avenue, orders lower carport roof

The San Anselmo Planning Commission on Feb. 3 approved a conditional use permit and design review allowing construction of a two-story, 1,153-square-foot detached accessory dwelling unit (ADU) at 176 Oak Avenue, subject to a condition that the height of the proposed carport roof be reduced to the minimum height consistent with codes and functional needs.

The commission voted 5-1 to approve the project after a lengthy presentation by staff and the applicant and public comment by the property owner. Acting Chair Tim Hyman cast the lone no vote; Commissioners Koblek de Leon, Pipkin, Smith, Asselstine and Tunney voted in favor.

The ADU proposal calls for 818 square feet of living space with two bedrooms and one bathroom, plus a 240-square-foot deck, a 47-square-foot elevator, 288 square feet of lower-level storage and a two-car open carport with a butterfly roof. Jackson Jabroni, assistant planner, told commissioners the project site is a steep, approximately 30,600-square-foot lot in the Bald Hill area with a 132% slope, an ephemeral creek along the north property line and an existing single-family house that previously received a height variance. Jabroni said the town received two written neighbor comments about foundation/engineering, bulk and potential light impacts; staff recommended approval with conditions, including required soils reports and building-code compliance.

Architect Alex Hecker described the design as a downslope ADU with an open-sided carport above the dwelling to provide off-street parking and emergency vehicle access. Hecker said lighting would meet dark-sky standards and be baffled and installed on the underside of the carport. He added that the exterior materials—thermally modified red oak siding, matte-black standing-seam metal and dark-clad windows—were chosen to blend with the wooded site and to improve fire resistance.

Owner Ruth Ann Keen told the commission the immediate purpose is to house aging parents and provide long-term flexibility: “The purpose is actually all of the above,” she said, describing plans that could include family use or future rental.

Commissioners’ questions focused on carport height, visibility from adjacent properties, tree removal, and whether the ADU would be considered an accessory unit rather than a duplex. Staff and the architect explained grading, tree-permit requirements for heritage specimens, the calculation of height on the sloping site and state ADU rules that affect allowable size. The carport’s lowest interior clearance point was described during the meeting as between 7 feet and 8 feet 4 inches depending on measurement; the roof slope was a 2:12 valley in the design, which the architect said constrained how much the roof pitch could be altered without voiding product warranties.

Several commissioners expressed appreciation for the design and the materials but also urged minimizing the visual mass of the carport. Commissioner Gary (last name not specified) moved that the commission require the carport roof be reduced to provide a 7-foot clearance from the high point of the driveway to the underside of structure, with staff empowered to allow retention of the original height only if adequate grounds were found. The motion passed 5-1. Acting Chair Hyman noted the 10-day appeal period for the decision.

The resolution adopted by the commission finds the project categorically exempt under CEQA class 32 (infill development) and approves exceptions to the town’s ADU development standards for height, size and setback, and design review for deviations from objective ADU standards. Conditions include all standard building and public-works requirements and tree-permit compliance where applicable.

Because the project required exceptions to ADU standards (size and height) and included design deviations, the commission’s approval included specific direction to staff and the applicant to work to lower the carport roof as the commission specified before building permits are issued.