NH State Guide
Home improvement costs in New Hampshire.
Locally calibrated cost data for fifty trades, plus the permit rules, code gotchas, and building conditions that actually matter when you plan a project in New Hampshire.
Updated May 2026
Cost calibration
New Hampshire costs are about 4% above the national average.
New Hampshire runs modestly above the national average, with the southern tier (Manchester, Nashua, Portsmouth) pulled up by Boston-metro proximity. Cold-climate factors dominate: deep frost, heavy snow, ice dams, and old housing. The "Granite State" earns its name — ledge near the surface complicates excavation — and NH has high radon. No state sales tax slightly lowers materials cost.
BEA RPP
1.038×
Regional Price Parity
BLS Labor Index
1.05×
Trades-labor metro adjustment
Permits
Permits in New Hampshire.
New Hampshire enforces the state building code (IRC-based) with local enforcement; some small towns have minimal permitting. Electrical, plumbing, and gas are state-licensed. Shoreland and wetland rules add review near water.
Where to file: Municipal building department where one exists; small towns vary. Manchester, Nashua, Portsmouth have portals. Plan review 1-3 weeks.
| Trade | Required when | Citation | Typical fee | Homeowner DIY? |
|---|---|---|---|---|
| Plumbing | In-wall work, fixtures, water heater, gas | NH plumbing/gas licensing | $60-$225 | NoLicensed plumber/gasfitter required for most permitted work |
| Electrical | Circuits, panel, service, EV charger | NH electrical; NEC | $60-$225 | ConditionalOwner-occupied allowed in some jurisdictions |
| Mechanical (HVAC) | Heating systems, ductwork, refrigerant | NH mechanical | $75-$250 | NoLicensed contractor; heat pumps increasingly common |
| Building (structural) | Additions, structural mods, decks | NH State Building Code | $100-$700 | YesDeep frost-line footings; ledge may complicate |
| Roofing | Re-roofs, structural deck repair | Local | $75-$250 | YesHeavy snow loads; extended ice-and-water shield |
| Shoreland | Work near protected water bodies | NH Shoreland Water Quality Protection Act | varies | YesSetbacks + vegetation rules near water |
Code highlights
What catches DIYers in New Hampshire.
Five code rules that show up on inspector reports more than any others. Catch them before demo day.
Granite ledge
New Hampshire is the Granite State for a reason — bedrock is near the surface in many areas. Excavation for foundations, footings, and utilities can hit ledge requiring blasting or hammering, an unpredictable and significant cost. Get a site assessment before pricing excavation.
Deep frost + heavy snow
NH frost line runs 48-60 inches; footings must extend below. Snow loads are 50-90 psf in the north and mountains. Verified roof load calcs and extended ice-and-water shield are standard. Add ventilation against ice dams.
High radon (Granite State geology)
New Hampshire's granite bedrock produces high radon, including in well water. Air and water radon testing are common at sale. Air mitigation is cheap during construction; water radon may need separate treatment. Test both.
Old housing stock
NH has old housing, especially in the south and mill towns. Lead paint, knob-and-tube, and asbestos are common in pre-1950 homes. Pre-demo testing is wise. Budget 15-20% contingency.
No sales tax
New Hampshire has no state sales tax, slightly lowering materials cost relative to neighboring states. Modest but real on large material orders.
Local building conditions
What changes in New Hampshire.
New Hampshire home improvement is shaped by granite ledge, deep frost and heavy snow, high radon, and an old housing stock. Southern NH carries Boston-metro cost pressure.
Granite ledge
Bedrock near surface statewide
Excavation can hit ledge requiring blasting/hammering — unpredictable cost. Site assessment first.
Frost + snow
48-60 inch frost; 50-90 psf snow (north)
Deep footings; verified roof load calcs; ice-dam ventilation.
Radon
High in air and well water (granite geology)
Test both air and water. Air mitigation cheap during construction; water radon needs separate treatment.
Housing age
Old stock in the south + mill towns
Lead, knob-and-tube, asbestos common. Pre-demo testing wise. 15-20% contingency.
Southern NH labor
Boston-metro proximity
Manchester/Nashua/Portsmouth run higher. Northern NH is more moderate.
No sales tax
No state sales tax
Slightly lower materials cost than neighboring states.
Cost data
Top home improvement projects in New Hampshire.
Hire-it-out cost ranges for the most-searched projects, calibrated to New Hampshire labor + materials.
| Project | Cost range | Difficulty |
|---|---|---|
| AC Replacement → | $4,700–$9,400 | Hard |
| Attic Insulation → | $1,600–$3,700 | Moderate |
| Backsplash Tile → | $800–$2,600 | Easy |
| Baseboard & Trim Installation → | $700–$3,100 | Easy |
| Basement Finishing → | $15,700–$52,200 | Hard |
| Bathroom Remodel → | $6,800–$18,800 | Moderate |
| Bathroom Vanity Installation → | $400–$1,600 | Moderate |
| Cabinet Refacing → | $4,200–$12,500 | Moderate |
| Carpet Installation → | $700–$2,600 | Moderate |
| Ceiling Fan Installation → | $200–$600 | Moderate |
Need a specific project priced for your zip? Open the calculator →
Local contractors
New Hampshire Local Pros.
New Hampshire is on the Local Pros roadmap. We are sourcing from r/newhampshire threads, community recommendations, and NH licensing records. Ledge-excavation and cold-climate specialists noted separately.
See New Hampshire Local Pros →Plan your New Hampshire project