Can You Sell Your ADU Separately in San Diego?
Short answer: Yes, if your property is in a part of San Diego County that has actually adopted the rules. AB 1033, the state law that makes this possible, doesn’t do anything on its own. It just gives cities and counties the option to allow it. The City of San Diego has opted in. Unincorporated San Diego County has too, but on a different timeline. Whether you can sell your ADU as its own unit right now depends entirely on which one of those you’re in.
That’s the part of this story that gets lost in a lot of the headlines, so let’s untangle it.
What AB 1033 Actually Changed
AB 1033 took effect statewide on January 1, 2024. Before it, an accessory dwelling unit was legally stuck to the main house. You could rent it out, but you couldn’t sell it as a separate piece of property. If you sold the house, the ADU went with it, no matter how independent it felt.
AB 1033 opened a path around that, by letting a homeowner convert a property into a condominium structure, with the main house as one unit and the ADU as another. Each one gets its own deed. Each one can be sold, financed, and owned on its own.
Here’s the part that surprises people: AB 1033 doesn’t add any units to your property. It doesn’t let you build a second or third ADU you weren’t already allowed to have. All it does is change how ownership of units you’re already permitted to have can be structured. Think of it as a paperwork and legal-structure change, not a new-construction law.
For homeowners still deciding whether to add an ADU in the first place, Melina’s earlier piece on adding an ADU as a profitable move covers the rental-income side of that decision, which is a separate question from whether you’ll ever be able to sell it separately.
And it’s opt-in. The state made it legal for a city or county to allow this. It didn’t force anyone to. That’s why the honest answer to "can I sell my ADU separately in San Diego" starts with "which San Diego."
The City of San Diego vs. Unincorporated San Diego County
This is the distinction that actually matters if you’re trying to figure out your own situation, and it’s the one most articles gloss over.
The City of San Diego adopted its own ordinance, and it’s been in effect since August 22, 2025. If your property sits within city limits, this has been available to you for over a year already.
Unincorporated San Diego County is a different jurisdiction with its own government, and it moved on a separate, later timeline. The Board of Supervisors adopted the county’s version in March 2026, and it took effect in early April 2026. County staff were also directed to come back with additional provisions, including possible owner-occupancy requirements and a first shot for existing ADU tenants to buy before the unit goes to market, so some of the finer details there are still being worked out even after the ordinance itself took effect.
Other incorporated cities in the county, Chula Vista, Oceanside, Escondido, and the rest, each need their own separate ordinance too. Adoption in the City of San Diego or in the unincorporated county tells you nothing about whether your specific city has opted in.
If you don’t know offhand whether your address falls inside city limits or in unincorporated county territory, that’s worth confirming before you get much further into planning around this, since the rules, the timeline, and even the office you’d deal with are different for each.
What the Process Actually Involves
Where it’s allowed, selling an ADU separately isn’t a form you fill out and a fee you pay. It’s a subdivision process, similar in spirit to converting a duplex into two condos.
Based on San Diego County’s published guidance for its version of the ordinance, expect something like this:
- Your ADU needs a finalized building permit, or to be under construction with an active one, before this is even on the table
- Converting the property runs through a Tentative Map or Tentative Parcel Map, the same subdivision tool used for other condo conversions, not a simple administrative sign-off
- The actual Condominium Plan doesn’t get recorded until the ADU passes final inspection and gets its certificate of occupancy
- You’ll need consent from any lienholder on your mortgage, plus HOA authorization if your property already sits inside one
- A licensed surveyor or civil engineer has to prepare the plan defining unit boundaries and shared areas
- Once it’s a separate unit, it gets its own address
There’s also an ongoing piece a lot of people don’t anticipate: creating two legally separate units out of one property generally means establishing an HOA, with CC&Rs, bylaws, and dues, even if that HOA only ever has two members. Someone still has to manage and pay for shared driveways, utilities, and maintenance going forward.
None of this is small. It’s a real legal and construction process with real costs, and the exact fees, forms, and timelines vary by which city or county office you’re working with. That’s a conversation for a real estate attorney and your local planning department, not something to guess at from a blog post, no matter whose.
Why This Matters if You’re Thinking About Selling
If you already have an ADU, sold-separately status isn’t the only way to capture its value. Melina Rissone works with San Diego homeowners weighing exactly this kind of decision, and the math often comes down to timeline and effort as much as dollars.
Selling the whole property with the ADU intact, and simply pricing in the rental income or flexibility it offers, is usually faster and requires none of the subdivision paperwork. Melina has written before about how much of the sale price a San Diego seller actually walks away with, which is worth understanding either way, since commissions, transfer tax, and prep costs apply whether you sell one unit or two.
Splitting off the ADU as its own condo can unlock more total value in the right situation, particularly if the ADU is newer, self-contained, and in a location where a smaller unit sells well on its own. But it takes months, not weeks, and it only works at all if your specific jurisdiction has opted into AB 1033.
If you’re weighing whether to condo-convert, sell as one property, or hold and rent the ADU out, Melina can walk through your specific address, your ADU’s permit status, and what jurisdiction you actually fall under.
The bottom line: AB 1033 made separate ADU sales legal in California, but only where a city or county has chosen to allow it. In San Diego, that means the city (since August 2025) and unincorporated county areas (since roughly early April 2026), each under its own ordinance, its own process, and in the county’s case, still-evolving details. Other cities in the county may or may not have opted in at all.
If you’re trying to figure out whether this actually applies to your property, and what it would take to get there, Melina Rissone can help you sort through your specific jurisdiction, your ADU’s permit status, and whether a condo conversion is worth the time compared to simply selling. Please reach out to schedule a consultation.
Frequently Asked Questions
Does AB 1033 let me build a second ADU on my property?
No. AB 1033 only changes how ownership of ADUs you’re already allowed to have can be structured. It doesn’t increase how many units you can build.
Is selling an ADU separately legal everywhere in San Diego County right now?
No. It depends on whether your specific city, or unincorporated San Diego County, has adopted its own ordinance implementing AB 1033. The City of San Diego and unincorporated county areas each have, on different timelines, but other cities in the county may not have opted in at all.
How long does the process take?
Based on the county’s published process, it involves a subdivision map, final inspection and certificate of occupancy for the ADU, and formal HOA formation, so this typically runs months rather than weeks, not counting however long the underlying ADU construction itself takes.
Does my ADU need to already have a permit?
Generally yes. Most versions of this process require a finalized building permit, an active permit with construction underway, or, for some older unpermitted ADUs, qualifying for a specific state streamlining program aimed at bringing them up to health and safety standards.
What if I’d rather just sell my house with the ADU included?
That’s usually simpler and faster, with none of the subdivision or HOA-formation steps. Whether it nets you more or less than a separate sale depends on your ADU’s condition, your local market, and your timeline, which is exactly the kind of thing worth walking through with an agent who knows your specific area. Melina’s list of key considerations before selling a San Diego home is a good place to start.
