What to Know Before Selling a Home With an ADU in California

Dec 21, 2026 · By Oanh Nguyen · Broker & Loan Officer · Selling

Accessory dwelling units, or ADUs, have become common across San José and the East Bay. A backyard cottage, a garage conversion or an attached unit can add living space, flexibility and, for some owners, rental income.

When it's time to sell, an ADU can widen your buyer pool. Multigenerational families, buyers who work from home and investors may all be interested. But an ADU also brings extra questions. Buyers, appraisers and lenders will want to know whether it was permitted, how utilities work, who lives there and what records you have.

In this post, I'll cover what sellers should prepare before listing a home with an ADU: permit records, layout and access, utilities, rent records, tenants, disclosures and the questions buyers usually ask.

This is general information, not legal advice. ADU rules are set by state law and local ordinances, and they change. Check with your city's planning and building department and, for legal questions, a real estate attorney.

Start With Permit Records

The first question buyers ask is usually: Was the ADU permitted?

What to gather:

• Building permits for the ADU, including the final inspection sign-off.
• Plans approved by the city.
• Certificate of occupancy or final approval, if your city issues one.
• Permits for related work, like electrical service upgrades, plumbing or sewer connections.
• Any address assignment for the unit.

If you can't find your copies, your city's building department can often help you look up permit history. In San José, the city's permit center has information on building permits and ADUs.

If the ADU wasn't permitted or the permit wasn't finaled: that doesn't automatically stop a sale, but it affects disclosure, buyer interest, financing and how the unit is marketed. Some cities have programs to help owners legalize existing units. San José, for example, has an AB 2533 ADU and JADU legalization program. Talk with the city and, if needed, an attorney or a licensed contractor about your options before you list.

Describe the ADU Accurately

How you describe the ADU in your listing matters.

• Use accurate terms. A permitted ADU, a junior ADU (JADU) and an unpermitted space are different things. Don't call an unpermitted room an "ADU" without explaining its status.
• Square footage: be clear about the source. Public records may not include the ADU.
• Bedrooms and bathrooms: list the main home and the ADU separately so buyers understand the layout.

When in doubt, describe what's there and disclose what you know about its status. Your agent can help with the wording.

Layout, Access and Privacy

Buyers want to picture how the ADU works day to day.

• Separate entrance: does the ADU have its own door and path?
• Privacy: how close is it to the main house? Are windows or yards shared?
• Parking: is there dedicated parking for the ADU? Many state rules limit parking requirements for ADUs, but buyers still want to know what's available.
• Outdoor space: does the ADU have a patio or yard area?
• Accessibility: single level, steps, path lighting.

A simple floor plan for both the main home and the ADU helps buyers understand the property quickly.

Utilities

Utilities are one of the most common questions.

Know:

• Electric: shared or separate meter? Was the service panel upgraded?
• Gas: shared, separate or all-electric?
• Water and sewer: shared or separate? Any separate connection?
• Internet: how is it provided?
• How costs are split if a tenant lives there.

Gather recent bills or account information so buyers can understand costs.

Rent Records and Tenants

If the ADU is rented, buyers, especially investors, will want details.

Gather:

• The current lease and any amendments.
• Rent history and payment records.
• Security deposit records.
• Utility arrangements in the lease.

Remember: tenant protections can apply to ADUs too. Selling the home doesn't automatically end a tenant's lease, and showing an occupied unit requires proper notice. My post on selling a rental property covers tenant planning. Talk with a real estate attorney before giving any notice.

Disclosures

California sellers generally must disclose known material facts. For an ADU, this may include:

• Permit status and any open or expired permits.
• Known defects or repairs.
• Any notices from the city.
• Tenant information, as appropriate.
• Unpermitted work, if you know about it.

My post on California seller disclosures explains the basics. When in doubt, disclose and ask your agent or attorney.

How Buyers and Lenders Look at ADUs

Buyers often ask:

• Can I live in one unit and rent the other?
• Can family members live in the ADU?
• What would it rent for? (I share local rent data, not promises.)
• Was it permitted, and when was it built?
• Is there room to add more units under current rules?

Appraisers and lenders look at the ADU too. Whether an ADU is permitted can affect how it's treated in an appraisal. Whether a buyer can count ADU rental income depends on the loan program and lender guidelines. Each buyer should ask their own lender how their loan treats the ADU. I don't make promises about appraisal value or loan approval.

Pricing a Home With an ADU

Pricing works best with the most comparable sales.

• Sales of nearby homes with permitted ADUs, when available.
• Adjustments for the ADU's size, condition, layout and permit status.
• Rental income, which some investor buyers will weigh, though it doesn't set the price alone.
• The main home's own features: location, lot, condition.

Homes with ADUs can be harder to compare because there are fewer similar sales. I review both the main home and the ADU when building a pricing plan. My post on ADU properties as investments explains how buyers often evaluate them.

Preparing the ADU for Market

• Clean and stage it like a separate home. Show how it can be used: guest suite, rental, office or home for a family member.
• Make small repairs.
• Photograph it separately, with its own floor plan.
• If it's occupied, coordinate photos and showings with the tenant and give proper notice.
• Highlight the entrance, path and outdoor space.

Questions to Ask Before You List

1. Do I have the permits and final sign-off for the ADU?
2. Is the ADU described correctly in public records?
3. Are utilities shared or separate, and how are costs split?
4. Is the ADU rented, and what does the lease say?
5. Do I need legal advice about the tenant?
6. Are there any open permits or city notices?
7. What have similar homes with ADUs sold for nearby?

ADU Seller Checklist

• ☐ Gather permits, plans and final inspection records.
• ☐ Check public records for square footage and unit details.
• ☐ Document utilities: meters, accounts and costs.
• ☐ Gather lease, rent history and deposit records.
• ☐ Get legal advice before any tenant notice.
• ☐ Prepare disclosures, including permit status.
• ☐ Create a floor plan for both units.
• ☐ Stage and photograph the ADU separately.
• ☐ Price with comparable sales of homes with ADUs.

ADU vs. JADU: Know Which You Have

State law treats these two types of units differently, so it helps to know which one is on your property.

• ADU (accessory dwelling unit): a separate living unit with its own kitchen and bathroom. It can be detached, attached or a conversion of existing space, like a garage.
• JADU (junior accessory dwelling unit): a smaller unit created within the main home, with its own entrance and at least an efficiency kitchen. It may share a bathroom with the main home.

The HCD ADU Handbook explains the definitions and rules. Your permit records should show which type was approved. Using the right term in your listing avoids confusion and sets accurate expectations.

Insurance and Records Buyers May Request

Buyers often ask their insurance agent how the ADU will be covered, especially if it's rented. Having these ready helps:

• Your current homeowner's policy declarations page, so the buyer's agent can see how the ADU was described.
• Any landlord or rental coverage you carry for the unit.
• Roof, plumbing and electrical records for the ADU.
• Appliance manuals and warranties.

Don't share confidential details like your policy number publicly. Your agent can share documents with buyers at the right point in the process.

Common Mistakes

1. Calling an unpermitted space an ADU without explaining its status.
2. Not having permit records ready.
3. Unclear utility arrangements.
4. Forgetting tenant rules when planning showings.
5. Pricing as if the ADU adds a fixed amount. Value depends on many factors.

Key Takeaways

• Permit records are the first thing buyers ask about.
• Describe the ADU accurately.
• Utilities, access and privacy affect buyer interest.
• Rent records and tenant rules matter if it's occupied.
• Price with comps that include similar ADUs.

A Hypothetical Example

This example is made up to show the process. It is not based on any real home or client.

A seller has a home with a detached backyard ADU built a few years ago. Before listing, we pull the permit history from the city and confirm the final inspection. The ADU has its own electric meter but shares water with the main home.

The ADU is rented on a month-to-month lease. The seller talks with an attorney about notice requirements. We schedule showings with proper notice, prepare a floor plan for each unit and market the home to buyers who want space for family and to investors. The buyer chooses to keep the tenant in place.

Frequently Asked Questions

How I Can Help

I help sellers with ADUs gather permit records, describe the unit accurately, coordinate showings with tenants and price with the right comparisons. I can also help buyers understand financing questions in general, while each buyer's lender makes the final call. My staging company, OnStage, can stage the ADU so buyers see its full potential.

The Bottom Line

Selling a home with an ADU takes extra preparation. Gather permit records, describe the unit accurately, clarify utilities and access, organize rent records, follow tenant rules, disclose what you know and price with comparable ADU sales.

Selling a home with an ADU? Let's plan the sale. I'll help you organize the details buyers will ask about.

Sources

• California Department of Housing and Community Development (HCD), ADU Handbook: https://www.hcd.ca.gov/building-standards/adu/handbook
• City of San José, Accessory Dwelling Units (ADUs): https://www.sanjoseca.gov/business/development-services-permit-center/accessory-dwelling-units-adus
• City of San José, AB 2533 ADU and JADU Legalization Program: https://www.sanjoseca.gov/businesses/development-services-permit-center/accessory-dwelling-units-adus/ab-2533-adu-and-jadu-legalization-program
• City of San José, About Building Permits: https://www.sanjoseca.gov/businesses/development-services-permit-center/about-building-permits
• California Civil Code §1102 and following (Transfer Disclosure Statement): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CIV&sectionNum=1102
• California Civil Code §1954 (landlord entry and notice): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CIV&sectionNum=1954

Plan the sale of your home with an ADU. Call or text me at 408-780-1188, or email onrealtygroup@gmail.com.

Oanh Nguyen · Broker & Loan Officer · On Realty Group, brokered by LPT Realty · BRE #02133991 · NMLS 2020335

Equal Housing Opportunity.

Loan disclosure: Oanh Nguyen, Broker | Loan Officer, On Realty Group, brokered by LPT Realty, BRE #02133991, NMLS #2020335. This post is general education, not a loan offer, rate quote or commitment to lend. Loan programs, guidelines and eligibility change and are subject to lender review and approval.

Disclaimer: This post is general information only, not an appraisal or legal, tax or financial advice; data comes from the public sources linked above, is believed reliable but not guaranteed, and can change at any time.