New Hampshire building permits

Where to get a building permit in New Hampshire

Apply to the building department of the city, town or county where the property is (the steps).

New Hampshire state agencies

These offices set statewide codes or license the trades. They do not issue permits for most home projects.

Building code in New Hampshire

Every code family, edition and effective date is on New Hampshire building codes.

State rules on which work needs a permit

RSA 155-A:2, V-a; RSA 155-A:4, I

• Permit required for new construction or renovation. Before starting new construction or renovation of buildings and structures as described in RSA 155-A:2, I, the person responsible for such construction shall obtain a permit.¹
• Tent accessory to owner-occupied 1-2 family dwelling exempt. A building permit shall not be required for a tent of any size erected as an accessory structure on property that is an owner-occupied, one or 2-family dwelling.¹
• Local permit process applies. In municipalities that have adopted an enforcement mechanism pursuant to RSA 155-A:3, the permit under this section shall conform to the locally adopted process.¹

Homeowners doing their own work

RSA 319-C:15, II; RSA 153:36, I and VIII(c)

• Homeowner electrical allowed. Nothing in this chapter shall prevent a homeowner from making electrical installations in or about a single family residence owned and occupied by him or her or to be occupied by him or her as his or her bona fide personal abode.⁵
• Homeowner plumbing allowed. To a property owner or the property owner's agent who installs, repairs, or replaces plumbing in the property owner's own single-family detached or townhouse residence, including new construction, or any property owner or property owner's agent who makes minor installations, repairs, or replacements to the owner's property.⁶
• Owner-occupant fuel gas allowed. The license requirements of this subdivision shall not apply to anyone who performs fuel gas fitting within an existing single family, stand alone structure owned and occupied by the person who performs the fuel gas fitting work, and such structure is used as the individual's primary residence.⁶
• Exempt gas work must still meet codes and inspections. Notwithstanding any provision to the contrary, any person who is exempt under this paragraph shall perform fuel gas fitting work in accordance with applicable technical standards, and comply with any applicable code, application, and inspection requirements that may apply to the fuel gas fitting work performed.⁶

Contractor licensing

RSA 319-C:1; RSA 153:27 et seq.; RSA 310:13

• Electrical work for compensation needs a license. No electrician installation shall be made for compensation, unless made by an electrician or other person licensed by the office of professional licensure and certification, except as provided in this chapter.⁵
• Licensed business may get municipal permits. A licensed business entity may apply for and receive a permit from any municipality within the state.⁶
• Contractor responsible for code compliance. The contractor of a building, building component, or structure shall be responsible for meeting the minimum requirements of the state building code and state fire code.¹
• Plumbing exception for heating and water heating installers. The plumbing license requirements of this subdivision shall not apply to any person or business entity that performs plumbing in connection with the installation of any heating, cooling, air conditioning or domestic water heating systems, whether solar, oil, gas, or electric, or the installation and servicing of water treatment systems or swimming pools.⁶

Handyman limits

RSA 319-C:2, III-c; RSA 319-C:3, VIII

• Incidental electrical work defined. "Incidental electrical work" means a job of minor consequence which occurs by chance, not needing calculations.⁵
• Miscellaneous-job workers doing incidental electrical excepted. Regular employees of owners or lessees of real property doing incidental electrical work, or persons whose occupation is the doing of miscellaneous jobs of manual labor in the course of which some incidental electrical work is done.⁵

Deadlines for permit decisions and inspections

RSA 676:13, III

• 30 days. Upon the submission of a completed application, the building inspector shall act to approve or deny a building permit within 30 days; provided, however, that nonresidential applications or residential applications encompassing more than 10 dwelling units shall be approved or denied within 60 days.⁷

Private plan review and inspections

RSA 155-A:2, VI; RSA 676:4-b

• Municipality may contract a qualified third party. Any municipality that has adopted an enforcement mechanism under RSA 155-A:3 may contract with a local enforcement agency or a qualified third party for these services as an alternative to establishing the position of building official pursuant to RSA 155-A:3, and such agency or third party shall have the same authority as a building inspector as provided in that section.¹

Limits on permit fees

RSA 155-A:9

• Municipal fees allowed. The municipality may establish fees to defray the costs of administration, implementation, and enforcement of the state building code and any local amendments.¹

Selling a home with unpermitted work

RSA 477:4-a; 477:4-c; 477:4-d

• Listed disclosure items for 1-4 family sales do not name permits. Prior to or during the preparation of an offer for the purchase and sale of any interest in real property to be used or proposed to be used for a one to 4 family dwelling, the seller shall disclose, in writing, the following information to the buyer.⁸

What local governments may change

RSA 155-A:3, VII · in effect July 1, 2026¹

• Local deviation prohibited. Notwithstanding any other provision of law, no local legislative body shall enact or enforce any ordinance, adopt or enforce any rule, or implement any regulation that amends, overrides, or deviates from the state building code, or addresses any subject included in the state building code, except as otherwise permitted by this section or other statute, on or after the effective date of this section.¹
• No residential sprinkler mandates locally. No municipality or local land use board, as defined in RSA 672:7, shall enforce any ordinance, regulation, code, or administrative practice requiring the installation of automatic fire suppression sprinklers in any new or existing detached one- or two-family dwelling unit in a structure used only for residential purposes, or in existing buildings that contain, or will contain, no more than four dwelling units, unless fire sprinklers are existing or are required by a nonresidential occupancy.¹

Accessory dwelling units (ADUs)

RSA 674:71 to 674:73 · in effect August 31, 2026⁹

• One ADU by right, attached or detached. One accessory dwelling unit, which may be either attached or detached, shall be allowed as a matter of right.⁹
• 950 square feet. The total living space of the accessory dwelling unit shall not exceed 950 square feet unless otherwise authorized by the municipality.⁹
• 750 square feet. A municipality may not restrict the total living space to less than 750 square feet.⁹
• Owner occupancy may be required. A municipality may require owner occupancy of one of the dwelling units, but it shall not specify which unit the owner must occupy.⁹
• One added parking space maximum. If a municipality has established regulations requiring parking for the principal dwelling unit, it may require up to one additional parking space for each accessory dwelling unit.⁹
• Only building permits where zoning is silent. If a zoning ordinance contains no provisions pertaining to accessory dwelling units, then one accessory dwelling unit shall be deemed a permitted accessory use, as a matter of right, to any single-family dwelling in the municipality, and no municipal permits or conditions shall be required other than building permits, if required by statute.⁹
• No separate septic required. The applicant for a permit to construct an accessory dwelling unit shall make adequate provisions for water supply and sewage disposal for the accessory dwelling unit in accordance with RSA 485-A:38, but separate systems shall not be required for the principal and accessory dwelling units.⁹
• Conversions of existing structures allowed. A municipality shall allow accessory dwelling units to be converted from existing structures, including but not limited to detached garages, regardless of whether such structures violate current dimensional requirements for setbacks or lot coverage.⁹
• Detached ADU permitted. A municipality shall permit one detached accessory dwelling unit.⁹

Can local rules be stricter?

Local rules no stricter than single-family⁹