Can you build your own house in New Hampshire without a contractor’s license?

New Hampshire’s confirmed homeowner license exemption covers specific plumbing work¹. You can do plumbing in your own detached single-family home or townhouse, including a new house¹. An owner’s agent can also qualify under that plumbing provision¹. Your exempt plumbing work must meet New Hampshire’s plumbing code¹.

The plumbing exemption does not give you permission to do every licensed trade yourself¹. Ask the Office of Professional Licensure & Certification which board can confirm the rules for your planned work⁶. Describe the tasks you plan to do, beyond calling yourself an owner-builder. Ask about general-contractor licensing separately before deciding which work to hire out.

You have a narrower exemption for fuel-gas work in New Hampshire than for homeowner plumbing¹. The gas exemption covers an existing, stand-alone single-family structure you own, occupy and use as your primary residence¹. That existing-home condition does not support using the exemption to do gas fitting in a new house¹. Your exempt gas work must meet the technical standards, application rules and inspection requirements that apply¹.

You need a separate answer about electrical licensing in New Hampshire¹. The identified electrical exceptions cover regular employees doing incidental work for owners or lessees¹. Ask OPLC to confirm the electrical rule for your project before you plan to do the wiring yourself⁶.

Your New Hampshire municipality’s adopted process for enforcing building codes controls your local building-permit application⁴. Owning the home gives you no statewide exemption from building permits or inspections². Ask your municipal building official which building and trade applications you need for your house⁴.

New Hampshire’s state building-permit system excludes one- and two-family dwellings in municipalities without a local enforcement system². Do not assume the State Fire Marshal will issue a substitute building permit for your house there². The state application names the property owner as the applicant⁷. Call the State Fire Marshal if you need to confirm whether your project belongs in the state system⁷.

You must follow New Hampshire’s building and fire codes even where local enforcement differs⁵. Your project must also meet applicable land-use rules, including use, location and dimensional limits⁵. Ask your municipal building official which code edition applies to your application⁵.

For covered applications, you need property and applicant details, a work description, building area and construction documents⁴. You need planning or zoning approval when warranted⁴. Your ordinary completed application has a 30-day approval or denial deadline⁴. Ask what makes your application complete, since that is when the deadline starts⁴. A statewide homeowner building-permit fee remains unconfirmed. Ask for your municipality’s fee schedule before you budget.

New Hampshire’s county summaries list residential building permits as required in 7 counties and conditional in 3³. Those counts cover unincorporated land where municipal building-permit processes differ^3,4.

Grafton County, Sullivan County and Strafford County are in the conditional group because municipal rules differ³. Carroll County and Coos County are in the required group³. A conditional listing does not give you permission to skip a building permit³. Start with the county page, then ask your municipal building official about your exact parcel and proposed house⁴.

Settle your New Hampshire building-permit process before you start construction that requires a permit⁴. Ask your municipal building official for the application checklist, trade applications and inspection schedule^2,4. Confirm any trade-license rules with OPLC before you plan to do that work yourself⁶.

Under New Hampshire’s state building-permit system, the permit holder must request inspections before work is concealed⁸. Work that fails to meet the rules needs correction and another inspection, with a reinspection fee⁸. Your municipality can require a certificate of occupancy before you use the building⁸. You also need energy-code compliance certification before occupancy when that code applies⁸. Ask your municipal building official which documents must be accepted before you move in⁸.