Unpermitted work: how to spot it before you buy
Updated October 2, 2026 · 4 min read
Unpermitted work is construction done without the required permit, so the city never inspected it. It does not appear in permit records. You spot it by comparing the house with its permit history: a new kitchen, finished basement or added bathroom with no matching permit is the signal to ask questions before you make an offer.
Why it matters to a buyer
Once you own the house, the city treats the work as yours. If it is discovered later, you may be asked to get a permit after the fact, open up finished surfaces for inspection, or redo work that does not pass.
In 2018 CBS Chicago reported on a couple who bought a rehabbed bungalow and then learned the rehab had been done without city permits. Repairs were estimated at about $20,000. A Chicago alderman quoted in the report said that when a property is rehabbed without proper permits, the new owners are the ones left carrying the bag.
Signs to look for
- The listing says renovated or updated, and the permit history shows nothing for those years.
- The bedroom or bathroom count is higher than the county assessor's record.
- A finished basement, attic or converted garage with no permit for the conversion.
- A newer electrical panel, water heater or furnace with no matching permit.
- A deck, addition or enclosed porch that does not appear on older listing photos or aerial imagery.
What to do if the record and the house do not match
- 1Ask the seller directly whether the work had a permit and who did it.
- 2Ask the building department whether that type of work requires a permit there. Some work is exempt.
- 3Have your inspector look closely at the area.
- 4Talk to your agent or attorney about a price adjustment, or about the seller legalizing the work before closing.
A missing permit is a question, not proof
Cosmetic work such as painting, flooring and replacing cabinets usually does not need a permit. Records can also be incomplete, especially for older work. Treat a gap as a reason to ask, not as evidence that something was done illegally.
Common questions
Is it illegal to sell a house with unpermitted work?
Generally no. Houses with unpermitted work are sold regularly. Many states require sellers to disclose unpermitted work they know about, and rules differ by state, so ask a local agent or attorney.
Can unpermitted work be legalized?
Often, yes. Many building departments issue a permit after the fact, sometimes called an as-built or retroactive permit. The work has to be inspected and brought up to code, which can mean opening finished walls.
Does unpermitted work show up in a permit search?
No. A permit search shows permits that were filed. Unpermitted work shows up as an absence: visible work on the house with nothing in the record to match it.
Read next
Sources
This guide is general information, not legal advice. Permit rules vary by city and state. Confirm anything that affects a purchase with the local building department or a real estate attorney.