Buying a Bay Area Home with an Unpermitted Addition: A Decision File

Find out what unpermitted actually means

The phrase can describe a missing record, work outside an issued permit, an unfinished permit, or a structure built without an application. Those situations have different investigation needs. Ask the seller to identify the particular work and provide the evidence behind the description rather than discussing the whole house as if it has one approval status.

List additions, converted rooms, bathrooms, outbuildings and relevant system changes separately. Record each feature's current use and approximate history. Distinguish what the seller knows from what the agent inferred and what remains unverified. This prevents a minor documentation gap from masking a larger physical alteration, or vice versa.

Compare three kinds of evidence

First examine the permit record and scope descriptions. Use the proper local system, such as SF San Francisco: Permit and Complaint Tracking or the San José resources described in San José: SJPermits and SJePlans Help. Second compare the actual property with any approved plans. Third commission appropriate condition assessment. None of these checks substitutes completely for the others.

A finished room can be well maintained but undocumented. An issued permit can describe a plan that was never completed. An inspection report can flag a condition without resolving its entitlement or permit history. Keep these findings in separate columns so the purchase decision is based on the kind of evidence each check actually provides.

Estimate scenarios rather than one invented repair number

Ask the relevant professionals to distinguish investigation cost from potential correction cost. A useful estimate names the assumed approval pathway, known defects, inaccessible areas and excluded design or agency work. It also states what new fact could materially change the estimate.

For example, a hypothetical detached conversion may need only further document recovery under one scenario and substantial design and corrective construction under another. Until the applicable pathway and condition are established, presenting a single confident legalization price would be misleading. Ask what can be resolved within your decision period and what uncertainty you would inherit.

Account for future plans

Your intended use matters to the purchase analysis. If you plan a larger remodel, ask whether the existing discrepancy could affect that application. If you expect rental use, separately establish that the proposed use and relevant approvals are supported; the existence of a kitchen alone does not prove a legal rental unit.

For an existing San José ADU or JADU, the current San José: AB 2533 ADU and JADU Legalization is a starting point for discussing the available program. It is not a promise that any particular property qualifies or that correction will be inexpensive. Ask who will evaluate eligibility and what records they need before you rely on the program in a purchase calculation.

A practical document request

Request permit numbers, approved drawings, inspection results, final documentation, notices or open-case information disclosed by the seller, and invoices explaining the disputed work. Ask your real-estate and legal advisers how unresolved facts should be handled in the transaction. Do not use a generic article to invent a disclosure rule or contract contingency.

End the investigation with a short decision summary: confirmed approved scope; physical concerns; missing documents; agency questions; cost scenarios; and the effect on your plans. A decision to proceed can be reasonable only in light of understood uncertainty. Equally, an unpermitted label by itself cannot tell you the technical condition or total financial consequence.

A due-diligence meeting agenda

Ask each adviser to address their own question. The building professional describes observed condition and investigation limits. The designer or permit consultant identifies the likely approval questions and documents needed. The real-estate and legal advisers explain transaction options using the actual contract and disclosures. Keep their conclusions separate enough that one person's expertise is not presented as covering every issue.

For each unresolved item, ask how it affects your planned use and what evidence would reduce uncertainty. A buyer intending only routine maintenance may have different practical priorities from one planning immediate expansion, although neither should be told that uncertainty disappears. Record what you would be accepting if the transaction closes before the investigation is complete.

A useful final page has no reassuring slogan. It lists confirmed facts, remaining uncertainties, estimated investigation cost, conditional correction scenarios and decisions made with professional advice. Keep the supporting documents. If you buy, that packet becomes the starting point for future work rather than another set of oral recollections passed from one owner to the next.