In late September, something big happened: SB 9 was signed into law, effectively ending single-family zoning in California. Depending on where you get your news, it was big for one of two very different reasons. To some, it heralded the end of the suburbs, an assault on the “suburban lifestyle dream.” To others, it signaled the beginning of the end of exclusionary zoning in California. The reality, as these things tend to go, falls somewhere in between. But what is single-family zoning? What does SB 9 change? And what does all this mean for the Golden State?
Single-family zoning is a regulation that prohibits a property owner from building anything more than a detached single-family home on his property. These zones often require large front and rear lawns, a two-car garage, and a strict 2.5-story height limit, a rigid set of design parameters that have defined the form of the modern American suburb. Crucially, all of this means that building denser, more affordable housing—like townhouses, duplexes, or small apartment buildings—is effectively illegal.
In big California cities like San Jose and Los Angeles, single-family zoning covers 94 and 62 percent of all residential areas, respectively. In smaller, more affluent suburbs—think Palo Alto or La Cañada Flintridge—virtually all residential land will be subject to single-family zoning. In light of the extreme housing shortages plaguing the state, this policy has naturally come under heavy fire.
How does SB 9 change all of this? The bill permits homeowners across the state to subdivide their home to create up to four homes. That is to say, homeowners can take their existing property, split it in half, and build a home and accessory dwelling unit (ADU) on each new lot. There are, of course, rules and exceptions: notably, the homeowner must continue to live in at least one of the units, and historic districts across the state are exempt from SB 9’s provisions. But where these conditions are met, single-family zoning is effectively dead.
Will this mean the end of the suburbs? Will it end California’s housing shortage in one fell swoop? Don’t count on either. On the one hand, uptake will likely be measured and largely invisible. Consider the 2017 reforms which legalized ADUs statewide, which probably deserves the title of ending single-family zoning in California. Far from the boom that doomsayers predicted at the time, ADU construction is only still ramping up. Even where construction is underway, the strict provisions regulating these ADUs mean that they are largely invisible to neighbors. Expect SB 9 to play out similarly.
And while a laudable step in the right direction, it’s hardly a silver bullet for the state’s ongoing housing crisis. According to researchers at the Terner Center for Housing Innovation at UC Berkeley, many homeowners cannot or likely will not utilize its provisions for one reason or another. The authors estimate that around 714,000 new housing units will be feasible as a result of SB 9, well-below the 1.8 million units that the state needs to build by 2025 just to keep up with population growth, to say nothing of Governor Newsom’s campaign promise of 3.5 million new homes.
The unexciting truth—not exactly the stuff of breathless headlines—is that SB 9 will likely make a small, slightly positive impact. It won’t destroy California’s suburbs, nor will it solve our housing crisis. And that’s okay. At most, a steady procession of duplexes will slip mostly unnoticed into historically low-slung suburbs. And onerous local regulations and clumsy permitting processes will continue to undermine the housing production our state needs. In scrapping one of the more excessive forms of land-use regulation—single-family zoning—SB 9 is a useful step forward. But take the extreme claims about its implications with a grain of salt.
