Commission approves variance to legalize unpermitted patio and deck at 550 Ralston Avenue

The Mill Valley Planning Commission unanimously approved a variance for 550 Ralston Avenue on Dec. 9 to legalize an unpermitted flagstone patio and an upper-level deck that encroached into required setbacks.

Associate Planner Michelle Johnson said both structures were constructed without permits and encroached over property lines and into required setbacks on the steep, 11,837-square-foot, downslope site. The city issued a stop-work notice in October 2022 for unpermitted interior and exterior renovations; staff have since required the owner to reduce the patio to within property boundaries and narrow the deck to maintain egress and safety standards. A building permit for corrective work has been issued, but final approval depends on zoning compliance through the requested variance.

Applicant Benjamin Wells told the commission he discovered the unpermitted work after buying the house and has taken steps to address safety concerns; he said he plans to keep excavated material on site and thanked staff for help navigating the process. "It was kind of an eye opener on the property," Wells said.

Commissioners noted the property's steep topography, substantial vegetation that provides screening and the distance to the nearest neighbor (about 120 feet), and concluded the requested variance would bring the site closer to compliance without creating adverse privacy or visual impacts. Commissioner Yolis moved to approve the variance and find the project categorically exempt under CEQA Section 15303; the motion passed unanimously.

The approval allows corrective reconstruction on the property consistent with the conditions set by staff and the building permit process.