Board approves ordinance requiring solar on new buildings up to 10 stories

San Francisco — The Board of Supervisors on Tuesday unanimously approved on first reading an amendment to the city's green building and environment codes that will require solar arrays to be installed when new buildings up to 10 stories are constructed.

The ordinance, authored by Supervisor Scott Wiener, changes the city's local code to move beyond the state's "solar-ready" requirement and require that the solar facilities actually be installed when the building is completed.

Supporters called the measure a straightforward step to expand the city's clean-energy footprint and reduce fossil-fuel use as San Francisco adds new rooftop area. "When we are reminded daily of our rapidly changing climate, it is so important that we continue our strong push to alter alternative non fossil fuel energies," Wiener said on the floor.

Nut graf: The change requires most new buildings up to 10 stories to install either photovoltaic panels or solar thermal systems on roof area equal to 15 percent of the rooftop (the state's existing solar-ready metric), rather than merely leaving the rooftop clear for future installation. Supporters said the ordinance makes immediate use of rooftop space while continuing a forthcoming second measure addressing green roofs.

Most of the discussion at the board focused on a technical exemption for certain facilities with intensive rooftop equipment, such as data centers and server farms. Supervisor Aaron Peskin and others cautioned that a broad exemption could be exploited to avoid the requirement, and Deputy City Attorney John Gibner explained how the amendment aligns the ordinance with existing building-code language about "primary function." "Primary function'is a major activity for which the facility is intended," Gibner said, describing why the change would narrow the exemption to facilities whose design makes rooftop solar infeasible.

Wiener offered several clarifications on the record and accepted a brief delay while city attorneys confirmed language. Later in the meeting the board approved an amendment replacing the phrase "electronic data processing" with the planning-code term "internet service exchange, as defined in section 102 of the Planning Code," narrowing the exemption further.

The ordinance won unanimous support on first reading after the technical amendments were accepted.

Ending: The law will return for a second reading and final passage; supervisors said a separate follow-up ordinance expanding rooftop requirements to encourage green roofs and additional renewable options will come later.