Can You Sell an ADU Separately from Your Home in California? What Makes It Possible
For decades, the answer to this question was a firm no. If you built an ADU on your property in California, it was legally tied to your primary residence. You could rent it out, let a family member live in it, or simply hold it as part of your overall property. But you could not sell it separately. The ADU and the main home were one legal entity, one parcel, one transaction.
That has started to change. A California law called AB 1033, effective January 1, 2024, created a legal pathway for homeowners to sell an ADU as a separate condominium unit, completely independent of the main house. The implications for California homeowners are significant: the ability to unlock property value without selling your home, create genuine homeownership opportunities for buyers who cannot afford a full single-family home, and redefine what ADU investment returns look like over the long term.
Here is everything you need to know about how it works, where it is available, and what it takes to do it in California in 2026.
What The Law (AB1033) Actually Does
Before AB 1033, California Government Code Section 65852.2 effectively prohibited the separate sale of ADUs from primary residences. An ADU could be built and rented but not independently owned.
AB 1033, signed by Governor Newsom in October 2023, amended that code to allow local governments to adopt ordinances enabling the separate conveyance of an ADU from the primary residence, treating both units as condominium units under a common interest development structure. In plain terms: the ADU gets its own legal identity, its own title, its own property tax account, and can be sold to a separate buyer while the homeowner keeps their main house.
The law is permissive, not mandatory. California cannot force cities to allow this. Each city or county must opt in by passing its own local ordinance before AB 1033 has any practical effect for homeowners within that jurisdiction.
Where AB 1033 Is Available in California Right Now
Because local adoption is required, availability varies significantly across the state. As of June 2026, the following jurisdictions have opted in:
San Jose was the first city in California to adopt an AB 1033 ordinance, in June 2024. By August 2025, San Jose had approved the first actual ADU condo conversions under the new law.
San Diego officially allows the sale of ADUs as condominiums as of August 22, 2025, through Zoning Ordinance Update O-21989.
San Diego County (unincorporated areas) adopted its ordinance on March 4, 2026, with the implementation taking effect April 4, 2026.
Santa Monica opted in during early 2025, allowing ADUs to be separately sold or conveyed as condominiums under specific conditions outlined in city code 9.31.026.
Santa Cruz allows ADUs to be mapped as condominiums, enabling separate sale.
San Francisco and Berkeley have both expressed interest in adopting AB 1033 and are actively exploring ordinances, though neither has finalized adoption as of this writing.
If you are not sure whether your city has opted in, the best step is to call your local planning department directly or contact ADUabl, as we track ordinance adoption across all California markets we serve.
How the Separate Sale Process Works
Selling an ADU separately under AB 1033 is not a simple transaction. It requires converting your property from a single-parcel ownership structure into a condominium common interest development. Here is what that process generally involves.
Step 1: Confirm your ADU qualifies. The unit must be fully permitted with a certificate of occupancy. Unpermitted units cannot be converted. The ADU must function as a truly independent dwelling, meaning it needs its own entrance, kitchen, bathroom, and sleeping area. Junior ADUs (JADUs) that share sanitation facilities with the main home are specifically excluded and cannot be sold separately under AB 1033.
Step 2: Condominium mapping. You must file a condominium plan with your city or county that legally maps the ADU and the primary residence as separate units within a common interest development. This requires a licensed surveyor or civil engineer and must comply with the California Subdivision Map Act. The map defines each unit’s boundaries, identifies shared spaces (driveways, yards, utility easements), and establishes how ownership is divided.
Step 3: Create governing documents. Because the two units now exist within a common interest structure, you need a set of governing documents: a Declaration of Covenants, Conditions, and Restrictions (CC&Rs), a condominium plan, and in most cases the formation of a two-unit homeowners association (HOA). The CC&Rs define each owner’s rights and responsibilities for shared areas and maintenance.
Step 4: Separate utilities. Lenders and buyers will typically require that the ADU have its own utility meters for electricity, gas, and water where possible. In some older properties, this requires infrastructure work to physically separate utility connections.
Step 5: Lienholder consent. If you have a mortgage on the property, your lender must consent to the subdivision of the parcel before the conversion can proceed. Most lenders require this formally and in writing. ADUabl can help coordinate this conversation with your lender.
Step 6: Buyer-first marketing requirement. In San Diego specifically, when an ADU condo is listed for sale it must first be offered to buyers who will occupy it as their primary residence. The seller must market it for at least 30 days on two public real estate websites with this disclosure before the sale can proceed without that restriction.
Step 7: Tenant protections. If your ADU is tenant-occupied at the time you apply for condo conversion, California’s Condominium Conversion Regulations apply. Your tenant must receive formal written notice well ahead of the conversion, and may have a first right of refusal to purchase the unit.
Important Restrictions to Know
Not every ADU qualifies, and not every sale can proceed without conditions. Here are the key restrictions.
ADUs built under affordability programs are restricted. ADUs created through the Bonus ADU Program or funded by the San Diego Housing Commission, CalHFA grants, or other affordability incentives typically have recorded deed restrictions that limit or prohibit separate sale. Units still under those covenant periods cannot be sold separately until the restriction expires. If your ADU was funded through an income-restricted program, check the deed before proceeding.
JADUs are excluded. A Junior ADU that shares bathroom facilities with the main home cannot be sold separately under AB 1033 and is not eligible for condominium conversion.
Owner occupancy rules for San Diego County. San Diego County’s April 2026 ordinance includes additional parameters to promote first-time homebuyers, including owner-occupancy requirements and a first right of refusal for existing tenants. Some of these specifics were still being finalized as of the implementation date in April 2026.
Only the ADU’s value is reassessed for property tax. This is actually an advantage worth knowing. When an ADU is sold separately, only the ADU unit undergoes property tax reassessment based on the sale price. The seller’s primary residence retains its existing property tax base under Proposition 13. The seller does not lose their long-term tax protections on the main home.
What This Means for Buyers
For buyers, AB 1033 creates something genuinely new in California: an entry point to homeownership that does not require purchasing a full single-family home.
A 500 to 700 square foot ADU in a well-located San Diego or San Jose neighborhood might sell for $300,000 to $500,000. That is still significant in today’s California market, but it represents a realistic ownership target for buyers who have been entirely priced out of traditional single-family home purchases in the same neighborhoods.
The San Jose story is instructive. One of the first ADU condo conversions in the state involved a 500 square foot detached ADU built behind a five-bedroom home. The homeowner’s in-laws in Sacramento had been wanting to move to the Bay Area for years but could not afford it. The ADU sale made it possible for them to buy a home in San Jose and live close to family. As the homeowner put it: “This opens the door considerably. It allows home ownership at a much more reduced cost.”
For buyers financing an ADU condo purchase, standard mortgage products apply. The unit must meet lender guidelines for a condominium purchase, including the two-unit HOA structure and the governing documents described above.
What This Means for ADU Homeowners Planning to Sell
If you currently own an ADU in a city that has adopted AB 1033 and you are considering whether a separate sale makes financial sense, here is the core question to work through.
What does your ADU generate in annual rental income, and what could it generate if sold as a separate condominium? A unit renting for $2,500 per month generates $30,000 per year in gross rental income. If that same unit could be sold as a separate condo for $450,000, the sale provides immediate capital that you can redeploy into the main home, into retirement, or into a new ADU build. The right answer depends entirely on your financial goals, how long you plan to hold the property, and what the local condo market looks like for units of your ADU’s size and condition.
It is also worth noting that an ADU built with the eventual intent to sell separately under AB 1033 should ideally be designed from the start with separate utility connections, a clearly independent entrance, and enough square footage and finish quality to command a strong price as a standalone condominium.
The Alternative: Lot Splitting Under SB 9
AB 1033 is not the only legal pathway to separating ownership of a property with an ADU. SB 9, enacted in California in 2021, allows homeowners to split a residential lot into two parcels, creating the possibility of separately selling each parcel. Unlike AB 1033’s condominium structure, SB 9 creates two distinct parcels with separate legal ownership rather than a common interest development.
Key SB 9 requirements include: both resulting parcels must be at least 1,200 square feet each, the lot split must comply with local zoning, and the homeowner must sign an affidavit stating they intend to occupy one of the resulting properties as their primary residence for at least three years. SB 9 is a more complex path than AB 1033 for most homeowners with an existing ADU, but it is worth discussing with a specialist if your lot size and configuration make it viable.
Lienholder Consent
When a borrower decides to implement AB 1033 to condo-ize and sell their ADU, it fundamentally changes the legal description and value of the property that serves as the collateral for their existing mortgage. Because of this, the state law requires the express written consent of every existing lienholder before a condominium map can be recorded with the county.
The lienholder has sole and absolute discretion over whether to grant this consent. Therefore, the likely outcomes for the lienholder position generally fall into three categories:
1. Refusal to Consent
The most restrictive outcome is that the lender simply says no. Because the original loan was underwritten based on a single-family residential property, a lender may be unwilling to modify the collateral to a fractional condominium interest. If the lienholder refuses consent, the condo conversion process is effectively blocked, and the ADU cannot be sold separately.
2. Demand for Payoff (Refinancing)
A very common outcome is that the existing lender will require the borrower to pay off the current mortgage entirely. The borrower would need to refinance the primary residence under its new legal description as a condominium unit. For borrowers holding onto historically low interest rates, this outcome can severely impact the financial feasibility of the ADU sale, as they will be forced into a new loan at current market rates.
3. Conditional Consent and Modification
The lender may agree to the subdivision but impose strict conditions to protect their investment. In this scenario, the lender would execute a partial release of the lien regarding the newly created ADU parcel while retaining their first-position lien on the primary residence. Conditions for this approval often include:
- Principal Reduction: Requiring a portion of the ADU sale proceeds to be applied directly to the principal balance of the existing mortgage to offset the reduction in overall collateral value.
- Collateral Modification: Securing approval to officially change the property’s legal description in the loan documents.
- HOA/CC&R Approval: The lender will likely require a review of the newly formed Homeowners Association documents, reserve thresholds, and shared maintenance agreements to ensure the primary residence’s value is protected from future neighbor disputes or deferred maintenance.
In Summary –
Yes, you can sell an ADU separately from your home in California, but the answer has meaningful conditions attached. You need a fully permitted, independent ADU, you need to be in a city that has adopted an AB 1033 ordinance, and you need to go through the condominium conversion process with the right legal and financial support.
As of mid-2026, San Diego, San Diego County, San Jose, Santa Monica, and Santa Cruz have all adopted enabling ordinances. San Francisco and Berkeley are working toward adoption. The number of cities opting in is growing steadily.
If you are in a participating city and you own a permitted ADU, this is a real option worth evaluating. ADUabl can help you think through whether a separate sale, continued rental, or a different financing strategy best serves your long-term financial goals. Contact Will Johnson Today.