San Francisco has this week passed landmark legislation requiring all new buildings under 10 storeys in height to be fitted with rooftop solar panels.

The city’s San Francisco Board of Supervisors unanimously passed the new rule on Tuesday, making the metropolis the largest in the US to mandate solar installations on new properties.

Smaller Californian cities such as Lancaster and Sebastopol already have similar laws in place, but San Francisco is the first large city to adopt the new standard.

From January 2017 all new buildings in the city with 10 floors or fewer must have either solar PV or solar thermal panels installed. The measure builds on existing Californian state law which requires all new buildings to have at least 15% of their roof space exposed to sunshine, in order to allow for future solar panel use.

Supervisor Scott Wiener, who introduced the legislation, said the new measure would put San Francisco at the forefront of the US fight against climate change.

“In a dense, urban environment, we need to be smart and efficient about how we maximise the use of our space to achieve goals such as promoting renewable energy and improving our environment,” he said in a statement.

Wiener is also working on legislation that will allow “living roofs” – which provide low-cost insulation, minimise storm flooding issues and provide new wildlife habitats – to also be eligible to meet the new requirements. The proposals are expected to be introduced in the coming weeks.

“This legislation will activate our roofs, which are an under-utilised urban resource, to make our city more sustainable and our air cleaner,” Wiener added.

San Francisco has a target to source 100% of its electricity from renewable sources by 2020 and has emerged as one of the US’s leading clean tech hubs with a raft of Silicon Valley investors and entrepreneurs backing a host of green technology start-ups in the region.