Home › New Hampshire
Remodeling a Home in New Hampshire: What Homeowners Should Know
We refer remodeling contractors in the Nashua region, the Salem, Derry and Londonderry area, Manchester and Bedford, and the Seacoast from Portsmouth to Rochester. New Hampshire leaves contractor vetting largely to homeowners and building permits to each town, so each town page covers what the local building department asks for. Call (978) 951-4644 or send the form. A person reads every request and replies with what happens next.
- Free for homeowners
- NH rules in plain English
- Nashua to the Seacoast
Ask About Remodeling Service in Your Area
Tell us about the house and the project you have in mind. A person reads it and replies with what happens next.
Please add your name, a 10-digit phone number and a valid email.
Your request didn't go through on our end. Please call (978) 951-4644 so it isn't lost.
Too many requests have come from this connection in a short time. Please call (978) 951-4644 and we'll take it from there.
We couldn't finish the spam check. Wait a moment and send it again, or call (978) 951-4644.
Service area
New Hampshire towns we cover
In New Hampshire the town or city issues building permits and may keep codes stricter than the state's, and zoning, historic districts and demolition review differ from one community to the next. Each town page covers the local building department and what it asks for, the rules for additions and accessory apartments, historic review and the kinds of homes you find there. Towns without a page yet are still in our area; send a request from any of them.
Nashua Region
Salem, Derry & Londonderry
Manchester & Bedford
Portsmouth, Dover & Rochester
State rules
Contractors, contracts and permits
No state contractor license. The Attorney General's Consumer Protection Bureau says "contractors do not need to be licensed" in New Hampshire. Its advice: ask for references from past jobs and from the suppliers the contractor uses, and ask each contractor for proof of insurance (NH Attorney General). The office has gone to court against remodelers who took deposits and did little or no work, including cases announced on June 9, 2023 (AG announcement, June 2023) and April 18, 2024 (AG announcement, April 2024).
Get it in writing. The same advice is to have a written contract before any work is done or any payment is made, listing the scope of work, materials, total price and payment schedule. A down payment over 50% of the final cost, or full payment before the job is finished, is a warning sign. Complaints go to the Consumer Protection Hotline at 1-888-468-4454 (Consumer Protection Hotline). The Consumer Protection Act also bars deceptive practices such as misrepresenting approvals or the quality of work, and lets a homeowner sue for damages (RSA 358-A).
Construction defects. When a contract to build or improve a home exceeds $5,000, the contractor must give a written notice that begins "NEW HAMPSHIRE LAW, RSA 359-G, CONTAINS IMPORTANT REQUIREMENTS YOU MUST FOLLOW BEFORE YOU MAY FILE A LAWSUIT." Under that law a homeowner serves written notice of a claim at least 60 days before suing, and the contractor has 30 days after the notice to respond (RSA 359-G).
Building permits. Permits and permit fees belong to towns and cities, and a town's code stays in force where it is stricter than the state building code (RSA 155-A:2). In a town that doesn't enforce the code, the State Fire Marshal does so only at the town's written request (RSA 155-A:7). The state building code moved to the 2024 editions on July 1, 2026, with a six-month concurrence period through December 31, 2026; beginning January 1, 2027 every permit request follows the new codes (Town of Merrimack code page).
Plumbing, gas and electrical. Plumbers and gas fitters must be licensed by the state (Mec 300), and electrical work done for pay must be done by a licensed electrician (RSA 319-C). The law exempts some owners working in their own single-family homes, but the work must still meet the applicable codes (RSA 153:36, RSA 319-C:15). Plumbers and gas fitters aren't in OPLC's online lookup; call OPLC at 603-271-2152 to check one (OPLC license lookup). The state electrical code is the 2023 NEC, effective July 1, 2025 (Town of Merrimack code page).
Last verified November 2026. Fees, restrictions and deadlines on this page are due for re-checking by January 2027.
Before you build
Apartments, old paint, radon and digging
Accessory dwelling units. Towns must allow accessory dwelling units in every zoning district that permits single-family homes, and one ADU, attached or detached, is allowed as a matter of right. The size cap is 950 square feet of living space unless the town authorizes more, and a town can't set it below 750. A town may require that the owner live in one of the units and ask for one extra parking space, but it can't require a family relationship, limit the unit to one bedroom or refuse a separate electrical panel and service (RSA 674:72, RSA 674:73). The unit needs its own sleeping, cooking, eating and sanitation facilities to count as an ADU (RSA 674:71).
Lead paint. New Hampshire is not an EPA-authorized state, so the federal rule applies directly: anyone paid to disturb painted surfaces in a home built before 1978 must be EPA-certified, sole proprietors included (EPA RRP). Small jobs that disturb six square feet or less per room inside are excluded, but window replacement and demolition of painted surfaces are always covered (EPA RRP for contractors).
Radon. State health officials say testing is the only way to know whether radon is in your home and offer free test kits to residents; the state's radon data brief passes on EPA's advice to test again after renovations (NH DHHS radon). That matters most before you finish a basement.
Digging a foundation. Excavation within 100 feet of an underground facility needs notice to Dig Safe at least 72 hours ahead, not counting weekends and legal holidays, and no more than 30 days ahead, with the dig area premarked in white (RSA 374:51). Dig Safe is free at 811 (Dig Safe).
Near the water. Construction, excavation or filling in the protected shoreland may need a state shoreland permit from the Department of Environmental Services first; some low-impact projects qualify for a permit by notification (RSA 483-B:5-b, protected shoreland).
What we refer
Remodeling projects, explained for New Hampshire homeowners
Kitchen Remodeling
New layouts, cabinets and counters, with licensed trades for any plumbing, gas and electrical work.
Bathroom Remodeling
Tub-to-shower conversions, full gut renovations and added bathrooms, permitted the way your town requires.
Additions & Whole-Home
Additions, dormers, second stories and whole-house renovations, with the structural permits and zoning they bring.
Attic & Basement Finishing
Turning an attic or a dry basement into living space, with the building department involved from the start.
FAQ
New Hampshire remodeling questions
Does a remodeling contractor need a license in New Hampshire?
No state license is needed for general remodeling. The Attorney General says contractors do not need to be licensed, so ask for references, the suppliers they use and proof of insurance. Plumbers, gas fitters and electricians do hold state licenses.
Is there a limit on how much a contractor can take up front?
The Attorney General's office treats a down payment over 50% of the final cost, or full payment before the job is done, as a warning sign. Put the payment schedule in a written contract before any work starts or any money changes hands.
Which building code applies to my project?
The state moved to the 2024 codes on July 1, 2026, and either code set may be used through December 31, 2026. From January 1, 2027, permit requests follow the new codes. Your town building department issues the permit and can tell you which set your application uses.
Can I build an apartment over the garage?
Towns must allow one accessory dwelling unit, attached or detached, by right wherever single-family homes are allowed. The default size cap is 950 square feet unless the town allows more, and a town may require that the owner live in one of the units.
What does it cost me to use New England Remodeling Pros?
Nothing. The request and the referral are free; the contractor prices the work.