San Diego County supervisors have cleared a new path to homeownership in the backyards of unincorporated communities, voting Wednesday to let accessory dwelling units be sold separately as condominiums. The move updates the county’s zoning code to match recent state law and is pitched as a way to create smaller, more attainable ownership options. It comes after months of outreach and a unanimous Planning Commission recommendation to stick closely to the state framework.
Board vote and what it does
During the Land Use session on March 4, the Board of Supervisors approved the ADU Ordinance Amendment, which updates the county Zoning Ordinance and creates an opt-in program so qualifying ADUs can be sold off as separate condo units, according to the county’s board packet as posted by San Diego County. The materials outline five different implementation options staff prepared for the Board and the specific ordinance language that would allow condominium mapping and separate ownership of ADUs.
County planning staff have also built out a project page that includes the draft ordinance and background explainers on how the local program is expected to function, according to County Planning & Development Services.
Supervisors split on investor concerns
Supporters on the board framed the ordinance as a way to stretch homeownership to more residents, while skeptics worried it could turn backyard units into a playground for investors.
“We need housing, and the ADUs make up a large portion of our new construction in San Diego County, unfortunately,” Supervisor Jim Desmond said, according to the Times of San Diego. He added that “If we’re gonna adopt an ordinance, I want it to be as flexible as possible to give homebuilders room to make their projects work.”
Supervisor Monica Montgomery Steppe, on the other hand, stressed that she wants to avoid a wave of buyers snapping up ADUs as investments rather than homes, according to the same reporting. In short, more units are welcome, but not a speculative rush on every backyard cottage.
How AB 1033 works
The county’s move is rooted in Assembly Bill 1033, a 2023 state law that lets cities and counties opt in to allow ADUs to be sold as condominiums. The statute lays out a fairly technical path: properties must go through condominium mapping, comply with the Davis–Stirling Common Interest Development Act and relevant portions of the Subdivision Map Act, and secure written consent from any lienholders before a split sale can happen. The full legal playbook is posted by California Legislative Information.
What comes next
The Board’s adoption was recorded March 4, and the updated ordinance is expected to take effect in about 30 days, according to the Times of San Diego. County staff have been directed to come back with program details, including ideas such as a tenant right of first refusal and other eligibility concepts, and staff-level recommendations are slated to return to the Board for direction in the coming weeks, per the same reporting.
The Planning Commission, for its part, favored adopting the state framework without tacking on extra local restrictions, according to San Diego County.
Why it matters
County documents show that ADUs made up a significant share of all permitted housing in 2024, which turns this policy tweak into a potentially powerful tool for expanding ownership opportunities in unincorporated communities, according to San Diego County. At the same time, those same materials warn that converting an ADU for separate sale is hardly a quick flip.
Owners who want to sell an ADU as its own condo unit will need to complete condominium mapping, form a homeowners association, and secure lender consent. Each step adds time and cost, which county staff note means the separate-sale option will be realistic for some homeowners but is unlikely to roll out overnight for most.
