Guide
Can I sell my ADU separately in San Diego County?
The short answer
Sometimes. Where local rules allow it, an ADU is sold as a condominium, and state law adds a narrow nonprofit route. Since April 4, 2026 the unincorporated County lets you map the house and the ADU as condominiums, and since September 18, 2026 each sale there also needs a 30-day public listing, a right of first refusal and the buyer's owner-occupancy affidavit. The City of San Diego allows ADU condominiums outside the Coastal Zone. In the 17 other cities it depends on the city's own ordinance, and a JADU can never be sold on its own.
What state law allows
By default an ADU can be rented out but not sold apart from the house. State law opens two ways around that.
- Condominiums, where your city or the County has chosen to allow them. Under AB 1033 the house and the ADU become separate condominium units, created under the Davis-Stirling Act and the Subdivision Map Act.
- A sale through a nonprofit. Every city and the County must allow an ADU, or a house, built or developed by a qualified nonprofit to be sold to a qualified low-income buyer who will live in it, under a recorded tenancy in common agreement that keeps the home affordable for 45 years.
A condominium ordinance has to include a few protections. Any lender with a lien on the property must consent in writing before the map or condominium plan is recorded, and it may refuse. An existing homeowners association must authorize the plan at a noticed board meeting. You must tell the water, sewer, gas and electric providers.
A JADU is different. Every JADU records a deed restriction that bars selling it apart from the house, and neither the County's program nor the City's covers JADUs.
In the unincorporated County
On March 4, 2026 the Board of Supervisors adopted a program that lets owners in unincorporated communities sell an ADU through a condominium conversion. It took effect on April 4, 2026.
It runs through a subdivision map, not a building permit. You apply for a Tentative Parcel Map for four or fewer units, or a Tentative Map for five or more, then record a Parcel Map or Final Map. A tentative map expires after three years if the final one is not recorded.
| Requirement | What the County asks for |
|---|---|
| The ADU's permit | A County building permit, either finaled or in progress for an ADU under construction. An ADU built without a permit before 2020 can first go through the County's AB 2533 path to a permit. |
| Number of units | No more than zoning allows. On a single-family lot that is the house and up to two ADUs. A condominium does not add units, and the ADU stays an ADU. |
| Consents | Written consent from every lienholder, attached to the condominium plan, and written authorization from any existing HOA. |
| Utilities | Proof that you notified every utility serving the property. On septic or a well, the Department of Environmental Health and Quality reviews capacity. |
| Documents | A condominium plan by a licensed surveyor or civil engineer, a plot plan, and CC&Rs that set up an owners' association, prepared before the County acts on the tentative map and recorded after the final map. |
| Timing | The condominium plan is recorded only after the ADU's final inspection and certificate of occupancy. A new address for the ADU is the last step. |
Since September 18, 2026 every sale of an ADU condominium in the unincorporated County carries three more steps. The Board adopted them on August 19, 2026 to favor buyers who will live in the unit.
- A public listing period. Each time a unit is listed, it has to be offered for at least 30 days on two or more public real estate sites that draw from the MLS, with a notice that it is offered to buyers who will live in it or house a family member there.
- A right of first refusal. Each condominium owner keeps a recorded, notarized right of first refusal with a rent-paying tenant or another owner on the lot. After the listing period, the holder gets written notice of the offer you choose and 30 days to match it.
- An owner-occupancy affidavit. The buyer signs a notarized affidavit, recorded at closing, that they or a family member will live in the unit as a primary residence for at least one year.
The director of Planning & Development Services can waive the listing period in some cases, and the right of first refusal when no one on the lot wants to hold it. In August 2026 the Board also asked staff to report back within 180 days on enforcing these rules, on deed restrictions and on allowing larger ADUs.
In the City of San Diego
Outside the Coastal Zone, you can turn a new or existing ADU into a condominium and sell it apart from the house. The rule came with the City's 2025 ADU amendments, in effect since August 22, 2025 and not yet certified by the Coastal Commission for the Coastal Overlay Zone.
- The condominium follows the City's subdivision rules, the Davis-Stirling Act and the Subdivision Map Act, on a single lot that was already mapped.
- The ADU must pass its final inspection before the condominium plan is recorded. For an ADU that already exists, you also need a housing quality standards report from an inspector certified by HUD.
- If any ADU on the lot has been lived in, the City's condominium conversion rules apply as well.
- Every lienholder must consent in writing, and you notify the utilities of the new condominium.
- For at least 30 days after it is first listed, the ADU has to be offered on two or more public real estate sites to buyers who will make it their home, under a covenant recorded before the mapping is finished.
- ADUs financed or assisted by the San Diego Housing Commission, and rent-restricted affordable ADUs, cannot be sold separately while their restriction lasts. A JADU never can.
A market-rate ADU built through the bonus program isn't named in that list, so the code doesn't bar its sale. But the Housing Commission holds a deed of trust on a bonus project, and no condominium plan records without every lienholder's written consent, so in practice the Housing Commission has to agree. The City's ADU page says bonus program ADUs can't be sold separately, so check with the City and the Housing Commission before you plan a sale.
The City's code also spells out the state's nonprofit route. HCD told the City in October 2025 that its version leaves out tenancy in common terms state law requires, and the September 2026 printing still reads the same.
In the 17 other cities
A condominium sale is a local choice, so it depends on your city's ordinance. Every city still has to allow the nonprofit route. The County's own guidance tells owners inside a city to ask that city's planning department.
- Coronado. Its ordinance bars selling an ADU apart from the house. In December 2025 HCD found that ban valid only for JADUs, told the city to allow sales that meet the nonprofit rules and suggested it consider condominiums.
- Coronado, since then. A local news report in August 2026 said the city agreed in February 2026 to amend most of HCD's 31 findings and named the ones it disputed. Separate sale was not among those named. We found no amended ordinance yet.
- Oceanside. Its 2026 ordinance allows separate sale only as state law's nonprofit route requires. In June 2026 HCD found that acceptable and suggested the city consider allowing ADU condominiums.
What changes the answer
These are the cases where a sale gets harder, or is off the table.
The Coastal Zone in the City
The City's condominium rules are not in effect in the Coastal Overlay Zone until the Coastal Commission certifies the 2025 amendments. The City's code page says it expects that in 2026.
A JADU
A JADU's recorded deed restriction bars selling it apart from the house, in every city and the County.
Affordable or Housing Commission ADUs
In the City, an ADU with San Diego Housing Commission financing or a rent restriction cannot be sold separately until the restriction ends.
A mortgage on the property
Nothing is recorded without your lender's written consent, and the lender may refuse or set terms. State law warns that you may have to pay off or refinance the loan, or get the lender to accept new collateral.
A homeowners association
If the property is already in an HOA, its board has to authorize the condominium plan at a noticed meeting, and the members too if its governing documents say so.
Utilities
For an ADU converted from existing space, a utility normally cannot require its own connection, but that protection ends when the ADU is sold as a condominium. In the County, a property on septic or a well needs a capacity review.
An ADU built without a permit
The County's program needs a County building permit, finaled or in progress. An ADU built before 2020 without one may get a permit first through AB 2533, after meeting health and safety standards.
Next steps
Confirm who your authority is, then weigh selling against renting.