Home › New Hampshire › Londonderry
Kitchen, Bathroom and Home Remodeling in Londonderry, NH
In Londonderry the building permit for an addition or remodel is still a paper application with an energy compliance form, while the electrical, plumbing and gas permits are filed online. Call (978) 951-4644 or use the form. A person reads every request and replies with what happens next.
- Free for homeowners
- Town and state remodeling rules on this page
- Kitchens, baths, additions and basements
Ask About Remodeling Service in Your Area
Tell us about the house and the project. 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.
Remodeling in Londonderry
What are you planning?
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.
Not sure what the town needs?
(978) 951-4644Tell us what you want to change and how many bedrooms the house has now, and we'll help you sort out what Londonderry will ask for.
Permits
Remodeling permits in Londonderry
Who issues them. Building & Zoning Enforcement is at 268B Mammoth Road, 603-432-1100 ext. 440, weekdays 8:30 to 5. Electrical, plumbing, gas/mechanical, wood and pellet stove, septic and well permits are filed on eSuite, but "Building permits are not available through our portal," so the building permit is a paper application (Building & Zoning Enforcement).
What needs a permit. The town's residential permit page covers "additions, remodels, renovations, sheds, decks, porches, garages," along with sunrooms, barns and carports, and notes a "$25 application fee required with each building permit submitted." The posted handouts include what to submit with an application, the Residential Building Permit Application and an Energy Compliance Form, with a separate application for accessory dwelling units (Residential permits).
Posted fees. The fee schedule effective November 4, 2025 charges $8 per $1,000 of value for residential additions, alterations and renovation, with the $25 application fee on every permit and a $50 residential minimum. Residential electrical additions and alterations are $100 plus $3 a device, plumbing $100 plus $16 a fixture, and mechanical $50 plus $10 for each additional item. A reinspection is $50 and after-the-fact permits are double (fee schedule).
- Building permits
- Building & Zoning Enforcement, 268B Mammoth Rd
- Phone
- 603-432-1100 ext. 440
- Building permit
- Paper application with Energy Compliance Form
- Trade permits
- Online on eSuite
- Remodel fee
- $8 per $1,000 of value plus $25 (effective November 4, 2025)
- After the fact
- Double fee
State rules. Towns issue permits and set fees under the State Building Code (RSA 155-A:2), and the 2024 code set has applied since July 1, 2026, with either set accepted through December 31, 2026 (state code summary). Because New Hampshire "contractors do not need to be licensed," according to the Attorney General, the vetting is yours: references, suppliers, proof of insurance, and a written contract with scope, materials, total price and payment schedule before any work or payment. Watch out for a deposit over 50% or a demand for full payment before the job is done (NH AG). Contracts over $5,000 carry the RSA 359-G notice, and a homeowner must give written notice of a defect 60 days before suing (RSA 359-G). Paid plumbing, gas and electrical work needs state-licensed trades.
Last verified November 2026. Fees, restrictions and deadlines on this page are due for re-checking by January 2027. New England Remodeling Pros is a referral service. We don't design or build; your contractor files the permits.
Zoning
Adding on in Londonderry
Setbacks. In the AR-I district, the zoning as amended through August 18, 2025 sets "Front - 40 Feet," "Side - 15 Feet," "Back - 15 Feet" for all uses, with 40 feet from each street on a corner or multi-frontage lot. Unsewered single- and two-family lots start at 43,560 square feet plus soil-based sizing, and a home with more than four bedrooms needs 15% more lot area for each extra bedroom (Section 4.2.1.3). Nonconforming buildings are covered in Section 8.2 (Zoning Ordinance); ask Building & Zoning Enforcement how it applies before enlarging a house that already crowds a line.
In-law units. The ADU Permit Instructions, revised November 4, 2025, split submittals into detached units (two sets of construction plans, a floor plan, the energy form and a plot plan) and an "Interior Renovation of Existing House" (floor plan and energy form). The floor plan must label every room and show the existing bedrooms. If total bedrooms including the ADU exceed the existing septic approval, "a new septic plan design must be approved by the state (but not installed)," and "The DES septic approval must be submitted with the permit application" (ADU instructions). Size and occupancy limits are in zoning Section 5.18; state law requires one ADU, attached or detached, by right wherever single-family homes are allowed (RSA 674:72).
Sewer and septic. The town sewer has 2,738 residential users (FY2027 sewer budget overview). Everywhere else, the local septic ordinance requires a Health Officer permit "prior to the commencement of any work," with inspections on 24 hours' notice (Chapter XIII).
Wetlands and floodplain. A Conservation Overlay District puts buffers around wetlands, and unavoidable buffer impacts go through the Conservation Commission to the Planning Board under the Buffer Mitigation Policy approved September 27, 2022 (Buffer Mitigation Policy). The town's 2025 hazard mitigation plan says that within the floodplain district no new development "which would increase flood levels during the occurrence of a 100-year flood event" is allowed without a variance, and it lists requiring elevation certificates among the town's flood insurance practices (Hazard Mitigation Plan). Footings need a free Dig Safe ticket at least 72 hours ahead, weekends and holidays excluded.
Historic review
Old houses and historic review in Londonderry
Historic Overlay District. The Heritage/Historic District Commission works under state law and "the Historic District section of the Town's Zoning Ordinance," and posts a Historic Properties Map, the Londonderry Look Book and its preservation task force report (Heritage/Historic District Commission). Exterior work in the overlay goes to the commission: a November 16, 2023 agenda shows an "Application for Certificate of Approval" for a post-and-rail fence on the Town Common, on a lot "Zoned AR-1 & Historic Overlay District" (HDC agenda, Nov. 16, 2023). For an addition or other exterior change to a property in the overlay, ask the commission before the design is final.
Demolition delay. The zoning has a demolition delay section, Section 9.3 (Zoning Ordinance), and in 2014 a Demolition Delay Committee voted to delay demolition of a 1799 house. We couldn't read the section's age threshold or delay length, so ask Building & Zoning Enforcement before any plan that takes down an older house or barn; a raze permit is $50 on the current fee schedule.
Lead. In a house built before 1978, anyone paid to disturb painted surfaces must be EPA-certified, and window replacement and demolition of painted surfaces are always covered (EPA RRP for contractors).
Londonderry's homes
Orchard country, mostly single-family
Londonderry counted 8,847 housing units, 7,346 of them single-family, 730 in buildings of five or more and 417 mobile homes or other units (NHES community profile, ACS 2009–2013). The zoning describes the AR-I district as land "developed for agricultural and forestry uses," and the Conservation Commission works to preserve "the community's orchards" (Conservation Commission).
The Town Common, home of Old Home Day, sits inside the Historic Overlay (Our Community). We found no official year-built figures for the town. Before finishing a basement, test for radon; the NH Radon Program offers free test kits (NH DHHS radon).
FAQ
Londonderry remodeling questions
Can I apply for a Londonderry building permit online?
Not for the building permit itself. The town says building permits are not available through its portal; additions, remodels and renovations use the paper Residential Building Permit Application with an Energy Compliance Form. Electrical, plumbing, gas and mechanical, septic and well permits are filed on eSuite.
What does a remodeling permit cost in Londonderry?
Under the fee schedule effective November 4, 2025, residential additions, alterations and renovation are $8 per $1,000 of value, plus a $25 application fee on every permit, with a $50 residential minimum. After-the-fact permits are double.
Will adding an in-law unit affect my septic system?
It can. The ADU permit instructions revised November 4, 2025 say that if total bedrooms, counting the ADU, exceed the existing septic approval, a new septic design must be approved by the state, though not necessarily installed, and the DES approval must be submitted with the permit application.
Do I need historic approval to work on an old house in Londonderry?
Inside the Historic Overlay District, exterior work goes to the Heritage/Historic District Commission for a Certificate of Approval; a 2023 agenda shows one for a fence on the Town Common. The zoning also has a demolition delay section. Outside the overlay we found no certificate requirement, but the building permit still applies.
What does it cost me to use New England Remodeling Pros?
Nothing. Asking is free for homeowners; the contractor prices the job, and the price and contract are between you and them.
Nearby