Merrimack County, New Hampshire Building Permit Guide

Building permits in Merrimack County come from its cities and towns. By the Census Bureau’s 2025 estimates the largest municipalities are Concord (44597), Hooksett (15346), Franklin (8839) and Bow (8415).

This guide covers the permit offices of the four largest municipalities. In Concord, start with the city’s online permit portal.

What requires a building permit in Merrimack County?

Merrimack County has no county building rules. Under RSA 155-A the state building code is enforced by the office each city or town appoints, and each town sets its own permit process and fees.

Concord’s residential guide exempts accessory structures and sheds no larger than 60 square feet, while in Bow a permit is needed for sheds over 200 square feet. Franklin says simple repairs such as new flooring or re-shingling do not need a permit.

Every building in New Hampshire must meet the state building and fire codes (the 2024 codes since July 2026). Only towns that have adopted an enforcement mechanism issue local permits, and any local amendment must be administrative and confirmed by the state. New Hampshire rules

Who handles permitting in Merrimack County?

Each city and town issues its own permits. Where a town has no enforcement agency and no third-party contract, the State Fire Marshal may enforce the codes, but only on the town’s written request.

Local rules in the largest Merrimack County towns

Concord

Permit applications go through the Citizen Self Service (CSS) Permit Portal, which also covers zoning, engineering (driveway, street excavation) and Fire Department inspection permits. The city’s residential guide says there is no charge for consultations.

Hooksett

Code Enforcement/Building, a division of the Community Development Department, issues building permits and certificates of occupancy. The online system covers electrical, gas, plumbing, fundraiser, yard sale and septic permits (allow at least 48 hours for review); all other applications are on the town’s Forms and Documents page.

Franklin

Building permits are administered by the Planning Office and must be filed there. Some electrical, plumbing or gas work can go through a Mechanical Permit, and in some cases the work can start as soon as the application is submitted.

Bow

Submit all plans electronically; the application needs 2 sets of construction plans (1 set 11x17 and 1 full set to scale). Minimum setbacks in the Residential and Rural Zones are Front 35 ft and Side and Rear 20 ft. For a new home the septic design must be approved by the Town of Bow and by the State of NH (DES) Sub Surface Bureau (603-271-3501), oil burners are permitted by the Fire Department (603-223-3960), and the driveway permit is approved by the Road Agent, or by State DOT on a State road.

Merrimack County permit costs and fees

Each municipality sets its own fees. Concord does not assess impact fees for non-residential construction. Hooksett’s Community Development Department posts a Notice of Building and Permitting Fees: a residential building permit is a $50 administration fee plus $0.15 per sq ft and a commercial one $50 plus $0.20 per sq ft, the rates the Town Council approved on October 28, 2015. Electrical and plumbing permits carry a $50 administrative fee plus per-item charges, and from the third inspection of the same request each re-inspection costs $25, to be paid before the certificate of occupancy or final approval.

How to get a building permit in Merrimack County

Inspections in Merrimack County

Franklin’s inspections are done by the Code Officers at the Franklin Fire Department after the permit is issued: call the Fire Prevention and Inspection Division at 603-934-5680 (Monday through Friday 8 am to 4 pm) and allow 24 hours to schedule. Concord’s Fire Department inspection permits are filed in the CSS portal.

Official Merrimack County permitting resources

These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.

• Concord permits and fees
• Hooksett Code Enforcement
• Hooksett Notice of Building, Permitting, Code & Inspectional Fees
• Franklin Building Department
• Bow Building / Code Enforcement
• RSA 155-A:7, enforcement of the state building code

Frequently asked questions

Is the Town of Merrimack in Merrimack County?

No. The Town of Merrimack is in Hillsborough County; its Building Division is covered in the Hillsborough County guide.

Do I need a permit for a shed in Bow?

Yes, if it is over 200 square feet.

Who inspects permitted work in Franklin?

The Code Officers at the Franklin Fire Department; call 603-934-5680 and allow 24 hours to schedule.

Simplify Merrimack County permitting with Alliance Permitting

• Confirm which town building office, or the State Fire Marshal, has the parcel and the project type
• Prepare the town application with any driveway, septic or fire department approvals it needs
• Schedule the town’s inspections and close out the permit

Alliance Permitting is a permit documentation and submission company in New Hampshire. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Merrimack County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.