Buying a House With Unpermitted Work: What to Check Before You Close

Buying a house does not come with a guarantee that everything visible was permitted. An addition, a finished basement, a new electrical panel, or a deck can all have gone up without ever going through the local building department, and the seller may not know that any more than you do. This guide covers what that can generally mean for your purchase, how to check permit history before you close, and what six states we have verified, Virginia, Maryland, New Jersey, Illinois, Massachusetts, and Pennsylvania, say about getting unpermitted work legalized after the fact. If the property you are buying is somewhere else, the concepts here still apply, but confirm your own state’s and locality’s rules before you rely on anything below.

What can unpermitted work mean for financing, insurance, and appraisal?

Unpermitted work can complicate a purchase in three places: the loan, the insurance policy, and the appraisal. An appraiser is valuing what physically exists against what public records say should exist, so a gap between the two, an extra bedroom or bathroom, a finished basement, added square footage, can affect what value the appraisal supports and what a lender is willing to finance against that value. A homeowners insurance carrier may ask similar questions when you apply for a policy, since unpermitted electrical, structural, or mechanical work that was never inspected is exactly the kind of risk an insurer wants to know about before it underwrites the policy, not after a claim comes in.

None of this works the same way at every lender, insurer, or locality. What a specific underwriter does with a known permit gap depends on their own policies and on the scope of the work involved. Treat this as a reason to find out what actually exists before you are relying on a closing date, not as a fixed rule that applies everywhere.

How to check permit history before you close

You can generally check whether work on a house was permitted using the same public records the local building department relies on. Start with Browse all permits to find the county or city we cover; our locality pages link out to that office’s own permit record lookup where one is published. Search the address for issued permits and compare what comes back against what you can see was actually built: an addition, a finished basement, a new deck, an upgraded electrical panel, a relocated bathroom. Work that is visible on a walkthrough but missing from the permit history is the signal worth chasing down before you sign anything.

If you are not sure which parts of a project would have needed a permit in the first place, Project Check walks through the specific type of work and your situation.

Can the work be legalized after you own it? Six states, verified

What happens after unpermitted work is discovered is not the same everywhere. Here is what we have verified for six states.

Virginia has no statewide as-built or investigation-fee process. Unpermitted work is handled through the violations system: a notice of violation directs the responsible party to correct it, in practice by applying for the permit that should have been pulled, within a reasonable time (13VAC5-63-150, USBC Section 115.2). Notices generally cannot go out more than two years after occupancy or final inspection, except on the advice of the locality’s legal counsel. For emergencies, work may start before the permit is filed as long as the application follows by the end of the next working day (Section 108.1).

New Jersey’s Uniform Construction Code has no general as-built process either. After-the-fact filing is allowed only for emergency work, application within 72 hours, and for minor work, notice before starting with the completed application filed within five business days. Outside those two narrow paths, the code still requires the owner to obtain the permit and pass inspection to resolve the violation (N.J.A.C. 5:23-2.14, 5:23-2.17A).

Maryland’s state building law does not set an as-built process at all, because it leaves permitting to local government. The state adopts model building codes, but each county or city implements and enforces them, issues the actual permits, and can adopt its own amendments, which prevail over the state standard (Md. Code, Public Safety 12-503 to 12-505). Whether, and how, you can legalize finished work in Maryland is a question for your county’s or city’s own permit office.

Illinois has the same structure for a different reason: there is no statewide administered residential building code at all. Building regulation is a municipal power, exercised under the Illinois Municipal Code’s enabling authority and, for larger cities, home rule authority (65 ILCS 5/1-2-1, 5/11-30-4). Whether a municipality has an as-built or after-the-fact process, and what it costs, is set entirely by that municipality’s own ordinance.

Massachusetts’ state building code has one after-the-fact provision, and it is narrow: for emergency repairs, the permit application has to be submitted by the next working business day (780 CMR 105.2.1, R105.2.1). There is no general as-built or retroactive process for non-emergency work already completed; unpermitted work is an unlawful act handled through violation notices and stop-work orders, and legalizing it runs through the local building official’s ordinary permit process.

Pennsylvania’s Uniform Construction Code regulations have the same shape: one emergency provision, letting a repair or equipment replacement proceed if the permit application follows within three business days (34 Pa. Code 403.62(b)), and no general retroactive or as-built process otherwise. Non-emergency unpermitted work is addressed through the code’s enforcement sections, and legalizing it means applying for the permit through the building code official, or in an opt-out municipality a certified third-party agency, the same way you would for new work.

Negotiate, hold back funds, or walk?

Whether to negotiate, hold money in escrow, or walk away depends on the scope of the unpermitted work and what your state’s or locality’s as-built path actually allows, not on a formula. If legalizing looks straightforward from what is verified above, an unpermitted deck or finished basement is often something you negotiate around: a price reduction, a seller-funded escrow held until the permit is closed out, or a post-closing repair agreement. If the work touches structural, electrical, or plumbing systems that were never inspected, or the jurisdiction’s after-the-fact path is unclear or effectively nonexistent, that changes the calculation, since you would be buying a known unknown with no verified path to resolve it. Get a licensed inspector’s opinion on the specific work, not just a general home inspection, before you decide which of these responses fits your situation.

If you are buying in one of these six states

We have verified the penalty and as-built rules for six states. If the property you are buying sits in one of them, start with that state’s page for the statute citations, the local permit offices we cover, and a form to get help with unpermitted work before you close:

• Virginia
• Maryland
• New Jersey
• Illinois
• Massachusetts
• Pennsylvania

If your state is not on that list, the same questions still apply, financing, insurance, permit history, and the as-built path, but confirm the specifics with your own state or local permit office rather than assuming they match what is verified here.