Committee backs ordinance requiring solar on 15% of new mid‑rise roofs

Supervisor Scott Wiener introduced an ordinance to require that new buildings between one and ten stories install solar systems on 15% of rooftop area rather than merely designating that area as "solar‑ready," citing state Title 24 and unanimous support from advisory commissions.

Barry Hooper of the Department of the Environment presented the department's cost‑effectiveness analysis and stakeholder outreach, noting that installation costs have dropped about 56% since 2008 and that the department found solar photovoltaics cost‑effective for the analyzed building types in San Francisco's climate zone.

Supervisor Erin Peskin questioned a provision exempting new Group B occupancy buildings where electronic data processing is primary. Hooper said the exemption responded to stakeholder concerns from facilities with distributed rooftop equipment, and he described stand‑alone data centers as a relatively rare use in San Francisco. Supervisor Wiener committed to refining the exemption's language before the full Board to ensure it remains narrowly tailored.

Industry and advocacy speakers supported the ordinance in public comment. Janine Cotter, a co‑founder of a local solar design‑build firm, said rooftop solar "is the democratization of our electricity supply" and urged San Francisco to lead other large cities. Bridal McEnany of the U.S. Green Building Council's Northern California office said the proposal raises the bar on sustainable building design and cited benefits of solar and green roofs for reducing greenhouse‑gas emissions and stormwater runoff.

Supervisor Wiener moved and the committee forwarded the ordinance to the full Board with a positive recommendation; the motion passed without objection.

The committee recorded staff commitments to refine exemption language and indicated forthcoming complementary legislation to allow green roofs as an alternate compliance option.