What must you disclose when selling a house in New Hampshire? By statute: written disclosure of the private water supply, sewage disposal system, and insulation (RSA 477:4-c and 4-d), plus buyer notifications about radon, arsenic, lead, PFAS, and whether the property sits in a federally designated flood hazard zone (RSA 477:4-a) — and, for homes built before 1978, the federal lead-paint disclosure (42 U.S.C. § 4852d). New Hampshire is otherwise a limited-disclosure state — often called a partial-disclosure or "buyer beware" state — which means no law forces you to volunteer everything you know, but the statutory list above is mandatory, it got longer on January 1, 2025, and you can still be sued for misrepresentation if you hide or shade the truth about something a buyer asks.
So "NH doesn't require disclosures" is a half-truth that gets sellers in trouble. The full picture has three layers: what RSA 477 requires in writing, what federal law adds for older homes, and what the customary New Hampshire practice — a full property disclosure form — asks of nearly every seller anyway. We walk our sellers through all three on every listing we take out of our Campton and Plymouth offices, and this guide walks you through them the same way. One note up front: we are a brokerage, not a law firm, and disclosure disputes are legal disputes — when your situation has a wrinkle, confirm the specifics with your closing attorney.
In this guide
- Is New Hampshire a disclosure state?
- The 2026 NH disclosure compliance checklist
- RSA 477:4-c and 4-d: water, septic, insulation
- RSA 477:4-a — the 2025 PFAS and flood additions
- Federal lead paint disclosure (pre-1978)
- The NHAR disclosure form
- Why honest over-disclosure protects sellers
- Mountain and lake property wrinkles
- Frequently asked questions
Key takeaways
- New Hampshire is a limited-disclosure state, but RSA 477:4-c and 4-d still require written disclosure of the private water system, sewage system, and insulation before or during preparation of the purchase and sale agreement.
- RSA 477:4-a, amended by HB 398 (signed July 3, 2024, effective January 1, 2025), added PFAS and federally designated flood hazard zone notifications to the long-standing radon, arsenic, and lead list.
- Federal law (42 U.S.C. § 4852d) separately requires lead-paint disclosure, an EPA pamphlet, and a 10-day inspection opportunity on homes built before 1978.
- The comprehensive NHAR property disclosure form is customary rather than statutory, and completing it honestly is the best liability protection a seller has.
- "Unknown" is a legally acceptable written answer; a false answer or active concealment can support a misrepresentation claim even in a buyer-beware state.
Is New Hampshire a disclosure state? Sort of — here is what the law actually says
Most states hand sellers a long statutory disclosure form covering everything from the roof to the neighbors. New Hampshire took a different path: a short list of mandatory written disclosures plus a set of mandatory notifications, layered over the old common-law rule of caveat emptor. In practice that means three things are true at once:
- You must disclose certain systems — private water, sewage, and insulation — in writing before or during preparation of a purchase and sale agreement, the P&S, which is the binding contract between you and the buyer (RSA 477:4-c and 4-d).
- You must ensure buyers receive statutory notifications about radon, arsenic, lead, PFAS, and flood hazard status before a purchase and sale agreement is executed (RSA 477:4-a).
- For everything else, you are not required to volunteer — but you are never allowed to lie, actively conceal a defect, or make a half-true statement that misleads. Misrepresentation and fraud claims do not care that New Hampshire is a "buyer beware" state.
If you are early in the process, our NH Seller Guide covers where disclosures fall in the overall timeline, and our pillar guide to selling a house in New Hampshire puts them in context with pricing, marketing, and closing.
The 2026 NH seller disclosure compliance checklist, statute by statute
Here is the whole obligation in one table — every item, the law behind it, what you actually have to hand over, and when. Print it, and check each row before your listing goes live.
| Requirement | Authority | What you must provide | When |
|---|---|---|---|
| Private water supply disclosure | RSA 477:4-c | System type and location, malfunctions, date of most recent water test, any known problems or contaminants — in writing; if unknown, state so in writing | Before or during preparation of the P&S |
| Sewage disposal disclosure | RSA 477:4-c | Septic system type, location, size if known, age, malfunctions, most recent service date, servicing contractor; whether connected to public sewer where it abuts one | Before or during preparation of the P&S |
| Insulation disclosure | RSA 477:4-d | Type and location of insulation, if known — "unknown" in writing is acceptable | Before or during preparation of the P&S |
| Radon, arsenic, lead notification | RSA 477:4-a | Statutory educational notification that these hazards occur in New Hampshire and testing is available | Before the P&S is executed |
| PFAS notification | RSA 477:4-a, added by HB 398, effective 1/1/2025 | Notification regarding PFAS (per- and polyfluoroalkyl substances) in the statutory language | Before the P&S is executed |
| Flood hazard zone notification | RSA 477:4-a, added by HB 398, effective 1/1/2025 | Whether the property is in a federally designated flood hazard zone, plus flood insurance information | Before the P&S is executed |
| Lead-based paint disclosure | Federal — 42 U.S.C. § 4852d (pre-1978 homes) | Known lead paint and hazards, any reports, the EPA pamphlet, and a 10-day inspection opportunity | Before the buyer is obligated under the contract |
| NHAR property disclosure form | Customary practice, not statute | Full property condition questionnaire — roof, systems, water, septic, hazards | Typically with the listing, before offers |
| No misrepresentation or concealment | NH common law | Honest answers to direct questions; no half-truths, no hiding evidence of defects | Always |
What RSA 477:4-c and 4-d require: water, septic, and insulation
The core of the NH seller disclosure form requirement lives in two short statutes. Before or during the preparation of an offer, the seller of real property with a residential dwelling must disclose, in writing:
The private water supply
If the property is served by a private water system — which around Campton, Thornton, and most of the Lakes Region means a drilled or dug well — you must disclose the type of system, its location, any malfunctions, the date of the most recent water test, and whether the seller has experienced a problem such as an unsatisfactory water test or one showing the presence of contaminants. Town water is common in village centers; nearly everything else up here is on a well, so this section does real work in our market.
The sewage disposal system
For private systems — septic tanks and leach fields, again the rule rather than the exception in the mountains — the statute requires disclosure of the system type and location, its size where known, malfunctions, the age of the system, the date it was most recently serviced, and the name of the contractor who services it. If the property abuts public water, you disclose whether the system is connected.
Insulation
For any building with a residential unit, you disclose the type and location of insulation, if known.
The statute contains one sentence sellers should memorize: if you do not know the answer, you say so — in writing. "Unknown" is a legally acceptable answer; a guess presented as fact is not. A seller who inherited a house and genuinely does not know when the septic was last pumped is far better off writing "unknown" than inventing a date. (Inherited sales raise their own set of questions — our guide to selling an inherited house in New Hampshire covers them.)
The RSA 477:4-a notifications — including the 2025 PFAS and flood additions most guides miss
Separate from the disclosure statutes, RSA 477:4-a requires that before a purchase and sale agreement is executed, the buyer receive written notification about specific environmental hazards. For years the list was radon, arsenic, and lead — standard language your agent or attorney builds into the paperwork.
Then the legislature passed House Bill 398, signed July 3, 2024 and effective January 1, 2025, which added two items: PFAS (per- and polyfluoroalkyl substances, the "forever chemicals" that have turned up in wells across parts of New Hampshire) and notification of whether the property is located in a federally designated flood hazard zone, along with information about flood insurance. These are now mandatory notifications on every residential sale.
Here is our honest observation from working listings every week: a surprising number of online guides — including national sites that rank at the top of search results — still describe the pre-2025 list and never mention PFAS or flood hazard notification at all. If you are selling in 2026 with paperwork copied from an old template or a for-sale-by-owner kit downloaded years ago, you can be out of compliance without knowing it. This is one of the quiet reasons working with a local team pays for itself; our sellers page outlines how we handle the paperwork side, and the compliance stakes are one of several reasons we caution people reading up on selling a house by owner in New Hampshire.
Practically, the radon/arsenic/lead/PFAS notifications are educational — they tell the buyer these hazards exist in New Hampshire and testing is available — while the flood item is property-specific: is the home in a FEMA-designated flood hazard zone or not. If your home sits near the Pemi, the Mad River, or low along a lake, check the FEMA flood maps before you list rather than after an offer arrives. We check them as part of pricing every riverside listing we take, for exactly this reason.
Federal lead paint disclosure for homes built before 1978
Layered on top of state law, federal law — the Residential Lead-Based Paint Hazard Reduction Act, codified at 42 U.S.C. § 4852d — requires sellers of housing built before 1978 to disclose known lead-based paint and lead hazards, provide any reports they have, give buyers the EPA pamphlet Protect Your Family From Lead in Your Home, and offer a 10-day window for a lead inspection. Given how much of New Hampshire's housing stock — village farmhouses, older lake camps — predates 1978, this applies to a large share of the homes we sell. It is a federal requirement with real penalties, and it applies regardless of New Hampshire's buyer-beware tradition.
The NHAR disclosure form: not required by statute, but customary — and smart
Now the part that confuses sellers most. Beyond the statutory items above, New Hampshire law does not mandate a comprehensive disclosure form. But in practice, nearly every listed home in the state comes with one: the New Hampshire Association of REALTORS property disclosure form, which walks through the roof, foundation, heating and electrical systems, water and septic, hazardous materials, and more. Buyers expect it, buyers' agents ask for it, and a listing without one raises the exact suspicion you do not want hovering over your negotiation.
Two rules make the form work for you instead of against you. First, answer what you actually know, and use "unknown" where you genuinely do not. Second, do not treat the form as a substitute for thinking — if you know something material that the form does not squarely ask about, tell your agent and put it in writing anyway.
Why honest over-disclosure protects sellers
It feels backwards, but the seller who discloses more is the seller who sleeps better after closing. The reasoning is simple: the legal risk in a New Hampshire sale rarely comes from the statute — it comes from misrepresentation claims. A buyer who discovers a chronic problem after closing, and can show the seller knew and concealed it or answered a direct question falsely, has a claim regardless of caveat emptor. A buyer who was told about the problem in writing before signing does not. Disclosure converts a future lawsuit into a present negotiation — and present negotiations are almost always cheaper.
A local example of what we mean. The calls we get every March are about the same thing: snowmelt, and water where water should not be. Plenty of solid mountain houses take on a damp corner of basement during a fast melt, and it is not a deal-killer — buyers up here understand ledge and spring runoff. The seller who writes "seasonal dampness in the northeast corner during snowmelt; sump installed 2021" sells the house. The seller who runs a dehumidifier for the photos and says nothing is the one who hears from an attorney the following April.
There is a market logic too. A disclosed defect gets priced once, calmly, up front. An undisclosed defect gets discovered by the buyer's home inspector two weeks before closing, at maximum leverage, and gets priced twice — once in the repair credit and once in the buyer's shaken confidence. Sellers who want to get ahead of that dynamic entirely can use our Ready-to-Sell Program, which includes a complimentary pre-listing inspection for qualifying listings and advances up to $2,500 in approved prep costs, reimbursed at closing: you learn what an inspector will find before buyers do, fix what is worth fixing, and disclose the rest from a position of strength. Knowing what your home is worth with those items priced in is the other half — start with a free professional home valuation.
How disclosures play out on mountain and lake properties
Our market — Waterville Valley, the Pemi Valley, the White Mountains, and the Lakes Region — adds disclosure wrinkles that a suburban guide never mentions:
Wells and water quality
Private wells dominate here, and New Hampshire's bedrock geology means naturally occurring radon and arsenic in well water are genuinely common. A recent water test is the cheapest credibility you can buy: it answers the statutory water-supply disclosure with data instead of memory, and it takes the scariest notification topics off the table.
Septic age versus bedroom count
Septic systems in New Hampshire are designed and state-approved for a specific number of bedrooms. If a "three-bedroom" camp has a septic approval for two bedrooms — a situation we see regularly with older lake properties that grew a bunk room over the decades — that mismatch belongs in the disclosure conversation, because the buyer's lender and inspector will find it. Know your system's age, capacity, and service history before you list.
Seasonal and private road access
Plenty of desirable properties up here sit on private roads or town roads that are not maintained in winter. Road maintenance agreements, plowing arrangements, and seasonal access limits are exactly the kind of material facts an out-of-state buyer cannot see in July — disclose them plainly. There is a financing angle too: buyers' lenders increasingly ask for a written, ideally recorded, private road maintenance agreement before they will close, so surfacing the road situation early protects your own transaction, not just the buyer.
Association documents in resort communities
In condominium and resort communities — Waterville Valley and Owl's Nest Resort among them — the disclosure conversation extends to association resale documents: budgets, reserves, pending special assessments, rental rules. Buyers are entitled to review them, their attorneys will read them, and a surprise assessment discovered late kills more resort-condo deals than any inspection finding. Gather the documents when you list, not when you are under contract.
Current use land
Larger parcels around Campton, Thornton, and up the valleys are often enrolled in current use under RSA 79-A, which taxes the land at its undeveloped value in exchange for keeping it open. Taking land out of current use triggers a Land Use Change Tax of 10% of the land's full market value. That is not a statutory seller disclosure item, but it is unquestionably material — a buyer planning a garage on the back acreage should hear about the current use lien from you, in writing, before the P&S.
Shoreland restrictions
Waterfront properties are subject to the state Shoreland Water Quality Protection Act (RSA 483-B), which limits cutting, construction, and impervious surfaces near the water. Buyers dreaming of a bigger deck or a cleared view should hear about those limits from you, not from the town after closing. Selling on the water has its own playbook — our guide to selling a lake house or second home in NH goes deeper.
Frequently asked questions
Is New Hampshire a full disclosure state?
No. New Hampshire is a limited-disclosure, buyer-beware state. But state law still requires written disclosure of the water supply, sewage system, and insulation (RSA 477:4-c and 4-d), plus buyer notifications about radon, arsenic, lead, PFAS, and flood hazard zone status (RSA 477:4-a) — and sellers remain liable for misrepresentation or concealment on anything else.
What is a seller legally required to disclose in New Hampshire?
Four statutory buckets: the private water system, the sewage disposal system, and the insulation, each in writing under RSA 477:4-c and 4-d; the RSA 477:4-a notifications covering radon, arsenic, lead, PFAS, and federally designated flood hazard zone status, delivered before the purchase and sale agreement is executed; federal lead-paint disclosure for pre-1978 homes; and honest answers everywhere else, because misrepresentation liability applies even where no statute does.
What are the new disclosure rules in New Hampshire for 2025?
House Bill 398, signed July 3, 2024 and effective January 1, 2025, amended RSA 477:4-a to add two notifications: PFAS (per- and polyfluoroalkyl substances) and whether the property is in a federally designated flood hazard zone, with flood insurance information. Both now apply to every residential sale, and many older forms and FSBO kits do not include them.
Do I have to disclose a leaky basement when selling in NH?
No statute names basements specifically — but if a buyer or the disclosure form asks and you answer falsely, or you actively conceal the evidence, you are exposed to a misrepresentation claim. Our advice is always the same: disclose it, price it, and move on. A known $5,000 issue negotiated up front beats a lawsuit later.
What happens if I don't disclose a problem?
If the problem falls under the statutory items, you have a compliance issue. Beyond that, a buyer who can show you knew about a material defect and concealed it or lied about it can pursue misrepresentation or fraud claims after closing — potentially for repair costs, damages, or in serious cases rescission. The specifics are legal questions for your closing attorney, but the pattern in the case law is consistent: the sellers who get sued are the ones who hid things, not the ones who over-shared.
Is a seller disclosure form required by law in New Hampshire?
The comprehensive form itself is not mandated by statute — only the specific water/septic/insulation disclosures and the hazard notifications are. But the NHAR property disclosure form is customary on virtually every listed sale, buyers expect it, and completing one honestly is the best liability protection a seller has.
Sell with nothing to hide — and everything priced right
Disclosure is where honesty and strategy point the same direction, and it works best when it starts before the sign goes in the yard. Our team preps every listing's disclosure package against the current statutes — including the 2025 additions — and our Ready-to-Sell Program can put a pre-listing inspection in your hands first. Start with a free professional home valuation to see what your home is worth in today's market, review what recent sellers walked away with on our sold listings, or talk with our team about your specific property. And if you are budgeting the whole transaction, our guide to seller closing costs in New Hampshire pairs well with an accurate valuation.
This guide is general information for New Hampshire home sellers, not legal advice. Rules change — confirm the specifics of your situation with your closing attorney.
Sources and further reading
- RSA 477:4-a — Notification Required; Radon Gas, Arsenic, Lead, PFAS, and Flood Hazard Areas
- RSA 477:4-c — Purchase and Sale Agreement; Water Supply and Sewage Disposal System; Insulation Disclosure Required
- RSA 483-B — Shoreland Water Quality Protection Act
- NH Coastal Adaptation Workgroup — New Hampshire's Flood Disclosure Bill Signed Into Law (HB 398)
- Fox Rothschild — New Hampshire Adds PFAS to Real Estate Sellers' Mandatory Notifications
- EPA — Real Estate Disclosures About Potential Lead Hazards