California has been on the cutting edge of renewable energy for quite some time, and a new housing mandate in San Francisco should cement that status even further.

According to Forbes, the San Francisco Board of Supervisors has unanimously approved a mandate known as the Betters Roofs ordinance. It will require new buildings of 10 stories or fewer to have solar panels on at least 15% of their rooftop area.

California already requires that 15% of roofs for new buildings are at least capable of accommodating solar panels, but San Francisco has decided to take things one step further. The mandate is similar to those passed in Lancaster, Sebastopol, and Santa Monica, but San Francisco is the first major city to adopt this new regulation.

The mandate is part of the city’s larger goal to transition to 100% renewable energy in the near future. While energy efficiency is a driving factor in this lofty goal, city officials are also expecting solar energy to help contain rising sea levels.

“San Francisco is already experiencing the repercussions of excessive CO2 emissions as rising sea levels threaten the city’s shoreline and infrastructure, have caused significant erosion, increased impacts to infrastructure during extreme tides, and have caused the city to expend funds to modify the sewer system,” legislators wrote in the Better Roofs ordinance.

Metal roofs are also widely accepted as an energy-efficient roofing solution, reducing energy costs by up to 20%. However, San Francisco is hoping that the benefits of renewable energy will also help to enhance the city’s corroded infrastructure.

As SolarNation reported, a recent study from North Carolina State University found that San Francisco residents stand to save an average of $187 per month by switching to solar energy, which is tied with Oakland for the highest in the nation. This is in stark contrast to cities like Philadelphia and Detroit, which each offer savings of only $81 per month.

Due to the attraction of lower energy costs and a rebuilt infrastructure, most San Francisans are quite pleased with the new mandate. However, there are some prospective home buyers who are concerned that theseadditional construction costs will be passed on to them.

Even after factoring in monthly energy savings and federal tax credits, a report from the city’s Department of Environment found that installation and maintenance costs for these new homes will be about $26,523 for a two-unit residential building, which is much higher than most people currently pay.

Despite the increase in up-front costs for solar panel installation, there is a widespread belief that these progressive changes will inevitably add up over time to save money for San Francisco residents.