InsulCalc

Insulation requirements in New Hampshire

Short answer

New Hampshire spans climate zones 5, 6. For most of the state (zone 6), the DOE recommends about R60 of attic insulation, with more in its colder areas.

Climate zones

5, 6

Most of the state

Zone 6

Recommended R-values for New Hampshire

Based on zone 6, which covers most of New Hampshire. Colder parts of the state (higher zones) need more — enter your ZIP for your exact numbers.

AreaRecommended R-valueBlown fiberglass
Attic / ceilingR6024.0"
Exterior wallsR20–R3012.0"
FloorsR3012.0"
Crawlspace / basement wallR15–R197.6"

New Hampshirerebates & tax credits

The federal 25C tax credit (30% of insulation materials, up to $1,200/yr) applies everywhere. New Hampshire's IRA rebate programs are administered by the state and rolling out on their own timeline. Check the official finder for New Hampshire's current status and how to apply.

Find New Hampshire's rebate programs →

Last verified 2026-07-07.

Your exact numbers

Enter your ZIP code

Other states

Frequently asked questions

How much insulation do I need in New Hampshire?

New Hampshire is in IECC climate zones 5, 6. For most of the state the DOE recommends about R60 in the attic, with more in colder areas. Enter your ZIP for the exact zone.

Are there insulation rebates or tax credits in New Hampshire?

Yes — the federal 25C tax credit covers 30% of insulation materials (up to $1,200/year), and New Hampshire's IRA HOMES/HEAR rebate programs (up to $1,600 for insulation) are administered by the state. Check the official finder for current New Hampshire status.

What climate zone is New Hampshire in?

New Hampshire spans IECC climate zones 5, 6; most of the state is zone 6. Your exact zone depends on your county — enter your ZIP to check.