WEST HOLLYWOOD/SANTA MONICA—The Los Angeles City Council unanimously passed a law that will require brittle concrete buildings and apartment buildings with large open spaces on the first floor to be retrofitted to withstand future major earthquakes.

About 13,500 wooden buildings and 1,500 concrete buildings will need to be upgraded in the SoCal area. Santa Monica is home to at least 2,200 buildings and West Hollywood has about 900 buildings.

According to KPCC, owners of the wooden buildings will have to be retrofitted within 7 years and concrete buildings have 25 years. The building upgrades are expected to cost tens of thousands of dollars for wooden buildings and hundreds of thousands of dollars for concrete buildings.

Building owners are expected to pay for the upgrades. The law allows owners to increase rent up to $75 a month, but a proposal from the city’s housing department asked that retrofitting costs be split evenly among landlord and tenants, capping costs for tenants at $38 a month.

“I certainly think that [paying for the upgrades] should be shared. This should not be something that tenants bear the burden of by themselves,” said Los Angeles Mayor Eric Garcetti in a statement.

The  buildings selected to be retrofitted came from a list compiled from maps, records, and surveys by researchers at the University of California-Berkeley.