The hard, grey, uninteresting rooftops that cover as much as 30 percent of San Francisco’s land area could be more beneficial to the city and to the environment. But more productive and sustainable uses of rooftops — solar panels, wind turbines, green stormwater infrastructure, urban agriculture, publicly accessible open space and natural habitat — are often more expensive to install and maintain. There are often barriers that prevent better uses from being easily implemented, and upgrading or retrofitting the roofs of existing buildings may be even more challenging.
Many cities around the world have incentives and even regulations requiring green roofs in new construction. But they're still seen as somewhat exotic and niche in San Francisco, and the city lags substantially behind others such as Portland, New York, Chicago and Toronto in both green roof policy and on-the-roof implementation. This report asks what can be done to support the development and broader implementation of green roofs in San Francisco. It considers the city’s existing policies that support green roofs and creates a policy roadmap for how to move forward on green roofs in the coming months and years.