Short answer
It can usually still be financed, but it can affect the appraisal, your insurance and what you may have to fix later. Appraisers working on conventional loans must comment on additions built without required permits and on how they affect value, and the space may not count toward the home's square footage. Ask the town's building department for the permit history before your inspection period ends.
How do I check a home's permits in New Hampshire?
Permits are kept by the town or city where the home is, usually by the building department or code enforcement office. In Hudson, Nashua, Manchester, Londonderry and most other towns you can ask for the permit file by address, and many towns let you search online. Compare it with the listing and the home inspection: a finished basement, bedroom, bathroom, addition, deck, or newer heating or electrical work should usually show a permit.
The assessor's property record card is another clue. If it lists fewer bedrooms or less living space than the listing, ask why.
How does unpermitted work affect the appraisal?
Fannie Mae's appraisal rules ask the appraiser to comment on the quality and appearance of an addition built without required permits and on its effect, if any, on market value. The appraiser may leave that space out of the living area or give it less value unless similar homes nearby have the same kind of space. That can lead to a lower appraisal than the price you agreed to. FHA and VA appraisals also look at whether the home is safe and sound.
What are the other risks?
- Safety: work done without inspections may not meet code, especially electrical, plumbing, heating and septic work.
- Insurance: an insurer may question a claim tied to work that was never permitted.
- Bedroom count: on a septic system, the approved design limits the number of bedrooms, so a bedroom added without approval can be a problem. See the well and septic guide.
- Future costs: the town may require a permit after the fact, which can mean opening walls or paying for repairs.
What can I do before closing?
During your inspection period you can ask the seller to get the permits after the fact, fix the work, lower the price or give a credit, or you can walk away if your contract allows. Your real estate agent and attorney can tell you which fits your contract. If the seller is getting permits, give the lender the final sign-off before closing.
Planning your own project after you buy?
If you want to finish the basement or add on after you move in, a renovation loan can roll the work into your mortgage, with permits as part of the process. See renovation loans in NH.
Sources
- Fannie Mae Selling Guide B4-1.3-05, Improvements Section of the Appraisal Report
- NH Department of Environmental Services, Subsurface Systems (septic approvals)
Checked November 2, 2026. Rules and dates change, so confirm current details before you rely on them.
General information only, not tax or legal advice. Program availability, eligibility and terms vary by lender and are subject to change and to underwriting approval. Not a commitment to lend.