SB9 and SB10 have passed the California Assembly and now await the signature of Gov. Gavin Newsom. If he signs them into law, it will be a transformational move away from single-family zoning in the state.

States including Minnesota (Minneapolis), Oregon, and Washington have passed similar legislation over the past several years. 

The two bills are designed to encourage more home construction in California, where housing is increasingly unaffordable for middle- and working-class people. 

SB9: California HOME (Housing Opportunity & More Efficiency) Act 

The main feature of SB9 is that it will allow homeowners to build a duplex on a single-family lot or to divide the lot into two separate parcels, each of which could then build a duplex.

That means potentially four units of housing on a parcel that once allowed a single-family home plus an ADU and a JADU.

Key features of SB9:

  • Homeowners in most areas around the state may divide their property into two lots.
  • Either one home or a duplex may be built on each of those lots.
  • Homeowners who want to split their lot must occupy one of the housing units as their principal residence for a minimum of 3 years from the time a lot split is approved.
  • Single-family homes may remain as they are—the bill does not mandate any new development.
  • The bill exempts homes in rural areas, historic districts, and properties that have been rented to tenants for at least 3 years.
  • The same owner (or any person acting in concert with that owner) may not purchase adjacent single-family lots for the purpose of this type of development. 
  • Cities may impose certain design standards.

Toni Atkins (D-San Diego), SB9’s author, says:

“This bill builds off the well-documented success of accessory dwelling units (ADUs), which have expanded options for homeowners who wish to be part of the solution in solving the housing crisis. In just two years, ADUs grew to comprise one-fifth of all new housing stock in Los Angeles.”

SB9

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SB10: Housing development in high-transit areas and urban infill lots

SB10 would authorize cities to upzone certain areas to allow up to 10 units on a parcel without having to go through the CEQA (California Environmental Quality Act) process. The parcels could include those currently zoned for single-family use.

Key features of SB10:

  • The parcel must be in a “transit-rich area” or an “urban infill site”; these terms are defined in the bill.
  • The height of the building may be specified by local jurisdictions.
  • Parcels in very high fire hazard areas are exempt.
  • Publicly owned open-space land or land designated for park or recreational purposes are exempt. 

To be clear, SB10 gives cities the right to adopt this upzoning, it does not itself enact the upzoning statewide.

We’ll be watching closely to see if Gov. Newsom signs one or both of these bills.

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Maxable is California’s leading ADU marketplace. After writing state laws, educating thousands of homeowners, and completing hundreds of site evaluations and ADU projects, we know accessory dwelling units better than anyone else! Get in touch when you’re ready to find out the next steps for your project.

SB9