California will require solar panels on all new homes. That’s not necessarily a good thing.

The California Energy Commission (CEC) recently voted 5-0 to add some new provisions to the state’s building code. Among them is the requirement that as of 2020, all new house and multi-family residences of three stories or fewer, along with all major renovations, must be built with solar panels.

Where solar is not suitable, homeowners must have access to a community solar project or receive efficiency upgrades that compensate. (There are some exceptions for buildings in highly shaded areas.)

California is currently adding 113,000 housing units a year, and that number is rising. Right now only about 15 percent of them are built with solar, so this is a big boost to the residential solar industry.