California has a severe shortage of middle-income housing or small (fewer than 10 homes) multi-family housing developments near jobs and transit; the lack of such housing is driving the displacement and severe rent burden of Californians across the state. The problem: it is illegal to build middle-income housing in over 70 percent of the state.

SB 9 would legalize this middle-income housing by adopting best practices from housing experts at the University of California Los Angeles. It will also help California respond to historic job loss in the construction sector and a 45-percent decrease in home construction due to COVID-19.

SB 9 makes two important changes to state law:

  • It allows homeowners in most areas around the state to divide their property into two lots, thereby increasing opportunities for homeownership in their neighborhood; and
  • It allows two homes to be built on each of those lots, with the effect of legalizing fourplexes in areas that previously only allowed one home.
  • SB 9 contains important protections against the displacement of existing tenants.

SB 9 is a part of the Senate’s Building Opportunities for All housing package. Learn more about this package of legislation here.


9/16/2021: SB 9 was signed by Governor Newsom and chaptered by the Secretary of State. This bill went into effect on January 1, 2022.


Authors: Atkins (D, SD 39), Caballero (D, SD 12), Rubio (D, SD 22), and Wiener (D, SD 11)
Co-authors: Gonzalez (D, SD 33), McGuire (D, SD 2), Robert Rivas (D, AD 30)


  • Council Member Jon Wizard, City of Seaside Council Member
  • Zach Hilton, City of Gilroy
  • AARP
  • Abundant Housing LA
  • ADU Task Force East Bay
  • All Home
  • American Planning Association, California Chapter
  • Bay Area Council
  • Bridge Housing Corporation
  • Cal Chamber
  • California Apartment Association
  • California YIMBY
  • Casita Coalition
  • California Building Industry Association
  • Chan Zuckerberg Initiative
  • Circulate San Diego
  • City of Oakland
  • City of San Diego
  • East Bay for Everyone
  • Facebook
  • Fieldstead and Company
  • Generation Housing
  • Greenbelt Alliance
  • Habitat for Humanity California
  • Hello Housing
  • Housing Action Coalition
  • Local Government Commission
  • Los Angeles Business Council
  • Midpen Housing
  • Modular Building Institute
  • Mountain View YIMBY
  • National Association of Hispanic Real Estate Professionals
  • Non-profit Housing Association of Northern California
  • North Bay Leadership Council
  • Northern Neighbors
  • Peninsula for Everyone
  • People for Housing – Orange County
  • San Diego Regional Chamber of Commerce
  • San Francisco Bay Area Planning and Research Association (SPUR)
  • San Francisco YIMBY
  • Sand Hill Property Company
  • Share Sonoma County
  • Silicon Valley Leadership Group
  • South Bay Cities Council of Governments
  • South Bay YIMBY
  • South Pasadena Residents for Responsible Growth