California’s New Housing Laws: Here’s What to Know

On Thursday, the state took a step toward creating higher-density neighborhoods as Gov. Gavin Newsom signed two high-profile housing bills.

Though the bills, Senate Bills 9 and 10, endured intense opposition in recent months, neither is all that revolutionary, said Conor Dougherty, a reporter for The New York Times who writes about economics in California.

But the package of housing reforms passed in California over the past four years, including these two latest measures, “is probably the biggest change in housing in 50 years or more,” Conor told me.

What the new laws will do

S.B. 9 allows duplexes to be built in most neighborhoods across the state, including places where apartments have long been banned. S.B. 10 reduces environmental rules on multifamily housing and makes it easier for cities to add high-density development.

The former has been the more controversial proposal, spurring angry opposition from homeowners and local government groups who have called it “the beginning of the end of homeownership in California.”

The classic California suburb — rows of houses, each with their own yard and fence — is largely a product of something called single-family zoning, a regulation that dictates that there can be only one house per parcel of land. These laws prohibit, say, building a high-rise in a residential cul-de-sac.

S.B. 9 essentially ends single-family zoning, but with a modest shift: Under the bill, property owners can build up to three additional units on their land, allowing single-family homes to be transformed into as many as four units.

A recent analysis by the Terner Center for Housing Innovation at University of California, Berkeley, found that S.B. 9 would most likely lead to 714,000 new homes across the state over the next several years.

What previous housing laws did

Though symbolically significant, S.B. 9 may not actually be as impactful as changes to housing policy that have already been enacted, Conor told me.

State lawmakers have been passing numerous housing reforms over the past four years in an effort to boost housing production. (Gov. Jerry Brown signed 15 housing bills in 2017, and Newsom signed 18 in 2019.)

Perhaps most significantly, California in 2017 relaxed laws to make it easier for homeowners to convert and rent out accessory dwelling units, the technical term for backyard homes — think “granny flats” or “in-law apartments.” Those rules have been further loosened since.

So even before S.B. 9 appeared on the scene, homeowners in California were allowed to have two units on a single-family lot — a main house and a separate guesthouse.

As these backyard dwellings continue to pop up, “people are going to complain that S.B. 9 is ruining their neighborhoods, when in fact they are actually unhappy about laws that passed semi-quietly several years ago,” Conor told me.