Press Release: Supervisor Wiener to Introduce Groundbreaking Green Roofs Legislation

Legislation will add green roofs, also known as living roofs, as an option to meet existing solar mandate requirement, making San Francisco the first city in the country with a comprehensive solar and green roof requirement

San Francisco Today Supervisor Scott Wiener will introduce legislation that builds on the groundbreaking solar roofs ordinance passed earlier this year by allowing green roofs, also known as living roofs, to satisfy the requirement under the solar ordinance. In April, the Board of Supervisors unanimously passed Supervisor Wiener’s legislation to require solar panels be installed on most new construction. This legislation made San Francisco the first major city in the country to require solar to be installed on new construction.

The new addition of green roofs to this requirement will make San Francisco the first city in the country to implement this regulation. France has advanced similar requirements that will go into effect in 2017. With the passage of this legislation, between 15% and 30% of roof space on most new construction projects will incorporate solar, green roofs, or a blend of both. Supervisor Wiener’s legislation was developed in coordination with the San Francisco Planning Department, the Department of the Environment, and SPUR.

“Climate change and our continuing drought demand that we take aggressive action to improve our city’s sustainability, for people living here today and for future generations,” said Supervisor Wiener. “Rooftops are one of the last untapped environmental resources in our growing city, and we need to be strategic about how we activate these spaces. Our solar requirement was a great step, and by adding green roofs to the mix, we will make our buildings greener, our air cleaner, and our city healthier. San Francisco can continue to be a national leader on environmental policies.”

Supervisor Wiener’s legislation builds on the existing solar requirement he authored, which requires that at least 15% of new roofs in buildings up to 10 stories in height must have solar installed. The green roof option will allow developers to replace solar with green roof at a rate of 2 square feet of green roofs for every 1 square foot of solar. That means that instead of doing 15% of the roof area as solar, developers can build out 30% of the roof area as green roofs, or, more likely a combination of the two.

“This ordinance, while genuinely pioneering, employs known and effective approaches that simply make sense: economically, aesthetically, and environmentally,” said Jeff Joslin, San Francisco Planning Department’s Deputy Director. “This is true at both the scale of the building, and for the City overall. It builds on San Francisco’s legacy of innovative stewardship, and will result in a city that’s greener, healthier and more sustainable.”

This legislation builds off the recommendations of the San Francisco Bay Area Planning and Urban Research Association (SPUR) Green Roof Task Force. First convened in August 2013, the Task Force set out to develop ideas for better and more sustainable use of San Francisco’s rooftops. The task force identified numerous public and private benefits of greener roofs, including energy savings, reduced stormwater runoff, improved air quality, ecological habitat, and prolonged life of the roof.

“Our research has shown that greener, better roofs bring many benefits to building owners and the general public alike,” said Laura Tam, Sustainable Development Policy Director at SPUR. “While rooftop solar increases our energy resilience and helps us avoid fossil fuel consumption, living roofs save building energy and prolong roof life, capture rainwater, provide ecological habitat, improve air quality, and reduce the urban heat island effect. This ordinance will demonstrate San Francisco’s environmental leadership by requiring new buildings to have solar or living roofs, and this policy will spur design innovation that may make it even easier for other cities to follow.”

Examples of existing living roofs in San Francisco include on the California Academy of Sciences in Golden Park, a mixed-use residential building at 38 Dolores Street, and 50 United Nations Plaza. The benefits of living roofs are numerous. They include:

  • Reduced quantity of stormwater runoff and improved water quality of the runoff
  • Reduction of the urban heat island effect (when built up areas are hotter than surrounding rural areas
  • Improved air quality
  • Building energy efficiency and energy savings
  • Open space for passive recreation
  • Aesthetic improvements
  • Noise reduction
  • Increase in habitat that promotes biodiversity
  • Extended life of the roof

The Planning Department has a website that details these benefits and more. This legislation will be heard at the Land Use and Transportation Committee in October.


The Solar Roof law was passed in April 2016 by a unanimous vote of the Board Of Supervisors and goes into effect on January 1st, 2017.

Under existing state law, California’s Title 24 Energy Standards require 15% of roof area on new small and mid-sized buildings to be “solar ready,” which means the roof is unshaded by the proposed building itself, and free of obtrusions. This state law applies to all new residential and commercial buildings of 10 floors or less.

Supervisor Wiener’s solar ordinance builds on this state law by requiring this 15% of “solar ready” roof area to have solar actually installed. This can take the form of either solar photovoltaic or solar water panels, both of which supply 100% renewable energy.

CA State Senator. Urbanist. Environmentalist. Advocate for transit, housing, clean energy, criminal justice reform, health, ending poverty. Democrat. 🏳️‍🌈

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