Planning Commission rejects wide citywide limits on ‘large‑home’ expansions, urges focused outreach

The San Francisco Planning Commission on Sept. 23 voted 6‑0 to disapprove a proposed Planning Code amendment intended to curb the conversion of modest single‑family houses into much larger luxury homes, but the commission attached a package of recommendations urging narrower, neighborhood‑focused outreach and technical revisions.

Jacob Bentliff of Supervisor Mandelmann’s office, the ordinance sponsor, said the measure was meant to address “a constant stream of existing 1,200 to 1,500 square foot older and relatively more affordable homes being converted into 4 or 5 or even 6,000 square foot luxury single family mansions” that “erode the city’s existing housing stock without adding any new housing supply.” The proposal would have triggered conditional use for very large expansions and included exceptions to encourage adding units rather than enlarging a single unit.

Commissioners and dozens of public commenters disagreed over whether the ordinance would achieve that goal. Architects and housing advocates told the commission the measure risked imposing burdens that would slow modest, family‑oriented home improvements and might do little to increase housing supply. Ozzie Ram of the San Francisco Land Use Coalition and several neighborhood groups said staff revisions risked encouraging demolition and could produce unintended displacement. Several speakers urged stronger tenant protections and clearer demolition rules.

Commissioners signaled multiple technical concerns during deliberations. They asked staff to examine whether a formulaic square‑foot threshold (2,500–3,000 sq ft) is the right tool across varied topography and lot sizes, whether FAR or form‑based rules would be more precise, how proposed ADU minimum sizes would interact with state ADU law, and how demolition calculations (Section 3.17) should be tightened for hotspots such as Noe Valley, Glen Park and Dolores Heights. Commissioner Tanner recommended reducing the suggested ADU minimum from 1,000 sq ft to something closer to 500–600 sq ft or leaving the minimum to further study.

Rather than vote to forward the ordinance as written, the commission adopted a motion of disapproval that included a package of recommendations: limit the ordinance’s initial scope to areas identified as hotspots (District 8 neighborhoods including Noe Valley, Glen Park and Dolores Heights), conduct broader outreach across affected neighborhoods, explore form‑based rather than simple square‑foot triggers, ensure the effective date and grandfathering use the ordinance’s effective date rather than a prior filing date, study tenant protections tied to demolitions, and refine how garages and unfinished spaces are counted.

The commission’s action means the measure will not be recommended in its current form to the Board of Supervisors. Commissioners said the Board may still pursue legislation; the Planning Commission’s unanimous disapproval and appended recommendations are intended to guide further drafting and neighborhood engagement.

The commission’s discussion — which drew sustained public comment and technical questioning — sets the stage for additional hearings on state housing laws (SB 9 and SB 10 were scheduled for future review) and for possible supervisor revisions that narrow the ordinance’s geographic scope and address the commission’s technical recommendations.