Window Replacement, Siding, Doors and Decks in Nashua, NH

Permits

Permits for siding, windows and decks in Nashua

Applying. The Building Safety Department has no online portal: applications are fillable PDFs sent to the department by email, and forms are also available at the Building Safety Department in City Hall, 229 Main Street (Permits; Building and Land Use Permit Application). Inspections run weekdays 8:30 am to 3:30 pm and can be requested by online form, email or phone (Building Safety Department). Fees are set by Ordinance O-21-045, but the ordinance and fee spreadsheet are posted as images, so ask the department for current amounts (fee spreadsheet).

What plans must show. The city's plan requirements for one- and two-family homes, covering new homes, additions, alterations and renovations, ask for window and door locations on the plans, at least two elevations, and proof of New Hampshire energy code compliance. Every sleeping room needs an emergency escape opening with a "minimum net clear opening of 5.7 square feet and 5 square feet for grade level" and a sill no more than 44 inches above the floor. Detached structures over 200 square feet need plans and review, and signs, electrical, plumbing, mechanical and demolition work need separate plans and permits (Plan Requirements). The city doesn't say whether a like-for-like siding or window swap needs a permit, so ask before work starts.

Building Safety Department

City Hall, 229 Main St

Apply

Fillable PDF applications by email; no portal

Deck footings

At least 48 in below finished grade

Simple decks

Typical deck plan handout

Bedroom egress windows

5.7 sq ft net clear opening (5 sq ft at grade); sill 44 in max

Porch removal

Demolition permit with Historic District Commission sign-off line

Building code

2024 codes since July 1, 2026; grace period through December 31, 2026

The code change. The Building Safety Department says New Hampshire's 2024 codes took effect July 1, 2026, with a grace period until December 31, 2026 (Building Safety Department); after it, permit requests follow the new code set (state code summary). Permits and their fees are reserved to cities and towns (RSA 155-A:2).

Hiring a contractor. New Hampshire doesn't license siding, window or deck contractors; the Attorney General says "contractors do not need to be licensed" and advises a written contract with scope, materials, total price and payment schedule before any work or payment, plus references and proof of insurance. A down payment over 50% of the final cost is one of the AG's warning signs (NH AG). On contracts over $5,000 the contractor must give you the RSA 359-G notice, and before suing over a defect you must give written notice at least 60 days ahead (RSA 359-G). Outdoor lights and deck outlets installed for pay need a licensed electrician (RSA 319-C:15).

Lead and asbestos. The city's lead program says "over 50% of the homes in Greater Nashua were built before lead paint was banned in 1978" (Lead Program). Anyone paid to disturb paint in a pre-1978 home must be EPA-certified, and window replacement is always covered regardless of size (EPA RRP). The city's Lead Paint & Healthy Homes Program, funded by a HUD grant, offers lead work for income-eligible households using only pre-qualified contractors (Lead Paint & Healthy Homes). For cement asbestos siding, an owner hiring the work out needs a state-licensed asbestos contractor and an inspection first, and NHDES must be notified at least 10 working days before a major abatement project; an owner removing it from their own single-family home is exempt from many of the rules but must still meet NHDES handling and disposal requirements, and the exemption doesn't apply within 6 months of selling or renting the property (NHDES asbestos; Env-A 1800).

Last verified November 2026. Fees, restrictions and deadlines on this page are due for re-checking by January 2027. New England Exterior Pros is a referral service. We don't do the work or file permits; the contractor does.

Decks and porches

Decks and porches in Nashua

Plans and footings. "For simple decks, you may use our typical deck plan handout." Complex decks need plans showing footing locations, elevations, stairs, rails and other details, and "Footings shall be a minimum of 48" below finished grade for frost depth protection" (Plan Requirements). The handout isn't posted online, so ask the department for it. Before digging, the excavator white-marks the area and notifies Dig Safe (811) at least 72 hours ahead, excluding weekends and holidays (RSA 374).

Wetland buffers. The land use code's buffer table sets 75 feet for primary wetlands, 40 feet for critical wetlands and other wetlands over 9,000 square feet, 20 feet for wetlands of 3,000 to 9,000 square feet and intermittent streams, and at least 100 feet for vernal pools (§190-112). Any use, building or structure in a wetland or buffer needs a wetlands special exception (§190-115).

Flood zones and shoreland. In mapped flood zones, the city's floodplain ordinance says "All proposed development in any special flood hazard area shall require a permit," which covers buildings and other structures, and calls for an elevation certificate for the lowest floor, including basements (Floodplain Development Ordinance). Separately, if a lot is in the state's protected shoreland, changing the dimensions of an attached deck needs an NHDES shoreland impact permit or permit by notification; a new deck on a nonconforming house may extend no more than 12 feet toward the reference line, and enclosing a porch or deck between a nonconforming house and the reference line is prohibited (NHDES shoreland FAQ). NHDES has a tool to check whether a lot is in the protected shoreland (protected shoreland).