How Can Buyers Check an Accessory Dwelling Unit's Permits and Use?

Ask the seller for the full permit history, approved plans, final inspections, and any certificate or local approval tied to the accessory dwelling unit. Match those records to the structure that exists today. Then ask the city or county building and planning offices what the records establish for the specific address and intended use. Arrange qualified physical inspection, and ask your lender, insurer, and attorney how the unit affects your own plans before a contract deadline passes.

I am Kate Fomina, a broker at Crypton Realty in Alameda. I help buyers organize the records and questions. I cannot certify that a unit is lawful, rentable, separately transferable, or valued at a particular amount. The local authority and qualified professionals make those determinations.

The image above is a fictional AI-generated image. It is not a real property, floor plan, permit, approved unit, rental, or transaction.

A listing may call a space an accessory dwelling unit, in-law unit, studio, cottage, or converted garage. Those words describe marketing, not necessarily legal status. The California Association of Realtors statewide advisory tells buyers to check with government agencies and qualified professionals about accessory-unit permits, legal requirements, current and future use, and rentability. It says brokers are not experts in those determinations.

Do not infer legality from a separate entrance, kitchen, utility meter, previous tenant, online map, or property-tax assessment. Each can be a clue for a question, but none replaces the permit and local-use record.

My Bay Area buying guide puts this investigation beside the rest of the property review.

Ask for approved building plans, permit numbers, inspection cards, final sign-offs, certificates, prior correction notices, and invoices for construction or later changes. Request any agreement or deed restriction tied to the unit and records about utility connections. Ask which part of the work was completed by the current seller and which predates ownership.

Check the address and parcel identifier on each record. A permit application is not an issued permit. An issued permit is not proof of a final inspection. A final inspection for one trade does not automatically cover every later alteration. Ask the building department to explain the status of each permit and whether the existing layout matches the approved plans.

My disclosure-package guide explains how to keep source documents and unanswered questions together.

Contact the city or county with the exact address and parcel. Ask which office holds building permits, planning approvals, and any occupancy or use record. Ask whether the structure is recognized as an accessory dwelling unit, which plans and conditions apply, and whether any permit remains open. Ask what additional review would be needed for the way you intend to use it.

Rules and records vary by jurisdiction and may change. Do not apply a neighboring city's rule to this parcel or assume a statewide law retroactively approved an older conversion. Get the response in writing where the agency can provide it, and record the date and staff contact. An attorney can interpret a disputed condition or recorded restriction.

The California Department of Real Estate buyer guide recommends professional inspection and careful reading of property disclosures. Use that approach for both the main home and the added unit.

Ask a qualified inspector to assess the actual structure and identify systems needing specialty review. The unit may have its own or shared electrical, plumbing, heating, roof, drainage, and foundation components. Confirm what is accessible and what is excluded from the general inspection. A professional should advise on safety or technical conditions.

Compare the observed layout with the approved plan. Note any later kitchen, bathroom, wall, window, or utility change and ask the local authority whether the record covers it. A seller's invoice can show work was paid for, but not that it received every required approval.

My second-showing checklist helps buyers revisit observable features before scheduling targeted specialists.

Ask the responsible local office about current rental-use rules for this address, including any recorded condition or permit limitation. Have an attorney review the effect on your plans. Do not assume that a prior rental was lawful, that a rental advertisement establishes permission, or that the future rules will remain unchanged.

If the unit is occupied, review the actual lease and tenancy with counsel. Ask about access, deposits, possession, and any local rental requirements. Do not treat projected rent as guaranteed income. A lender may have separate rules for using accessory-unit income in qualification, and a tax professional can address tax questions.

Keep the property-use inquiry about the unit and documents, not about the characteristics of current or future occupants.

Tell your lender about the unit early and provide the records it requests. The lender decides loan eligibility, documentation, and whether any rental income can be considered. The appraiser independently describes the property for the assignment. The Fannie Mae appraisal guide says an appraiser should describe an accessory dwelling unit and address additions without required permits under its standards.

Do not add the unit's area to the main home's living area without understanding the measurement and appraisal rules. Ask the lender and appraiser what figures they use. A seller's asking price or an online estimate does not establish the unit's contributory value or loan treatment.

My appraisal-gap guide covers the separate issue of a lender's value coming in below a contract price.

Give an insurance professional the actual structure, use, and occupancy details. Ask what would be covered under the proposed policy and whether a separate endorsement or policy is needed. Do not assume the main home's coverage automatically extends to every use of the added unit.

Ask the utility providers and qualified contractors whether services are shared or separate and what any change would require. A meter visible on the property is not proof of a lawful unit or independent service rights. Get written information for the property rather than relying on a general online guide.

Include likely utility and insurance costs in your ownership budget only after you have quotes or actual professional answers.

That is a legal and local-government question. Ask title and counsel whether the parcel and recorded documents permit any separate transfer, and ask the local planning authority about a proposed expansion. Do not infer either right from a fence, separate address, or current state-law headline. The existing approval may describe only the present configuration.

If your offer depends on future construction, identify the plan and get professional feasibility advice before relying on it. A conceptual sketch is not an issued permit. Ask about setbacks, utilities, access, and any recorded restriction with the relevant officials and specialists.

My buying process page shows how feasibility questions need to fit within inspection and contingency dates.

List each difference: area, number of rooms, kitchen or bath fixtures, separate address, completion date, or stated rental use. Ask the seller for the source of the listing claim and ask the local office what its file shows. Bring a material mismatch to your agent, lender, inspector, and attorney before removing a contingency.

Do not ask an agent to certify a unit from a photograph or call a room permitted because it looks finished. A local authority may need to inspect or review files, and that can take longer than the contract allows. Ask your agent and attorney what the signed agreement permits if the answer is not available by the deadline.

My contingency guide explains the risk of making a decision with an important property question unresolved.

Get the seller's permit and construction records, compare them with the actual unit, and ask the local building and planning offices about this address and intended use. Schedule qualified inspection and speak with the lender and insurer early. Bring disputed legal or tenancy questions to counsel before your deadline.

Read my Alameda County buying page for the broader offer plan. If you want help organizing the document and inspection questions, contact me. This is general real estate information, not a permit, land-use, legal, construction, lending, insurance, tax, or investment opinion.