Insulation requirements in Hawaii
Short answer
Hawaii spans climate zone 1. For most of the state (zone 1), the DOE recommends about R30–R49 of attic insulation, with more in its colder areas.
Climate zones
1
Most of the state
Zone 1
Recommended R-values for Hawaii
Based on zone 1, which covers most of Hawaii. Colder parts of the state (higher zones) need more — enter your ZIP for your exact numbers.
| Area | Recommended R-value | Blown fiberglass |
|---|---|---|
| Attic / ceiling | R30–R49 | 19.6" |
| Exterior walls | R13–R15 | 6.0" |
| Floors | R13 | 5.2" |
| Crawlspace / basement wall | Not required | — |
Hawaiirebates & tax credits
The federal 25C tax credit (30% of insulation materials, up to $1,200/yr) applies everywhere. Hawaii's IRA rebate programs are administered by the state and rolling out on their own timeline. Check the official finder for Hawaii's current status and how to apply.
Find Hawaii's rebate programs →Last verified 2026-07-07.
Your exact numbers
Enter your ZIP codeOther states
Frequently asked questions
How much insulation do I need in Hawaii?
Hawaii is in IECC climate zone 1. For most of the state the DOE recommends about R30–R49 in the attic, with more in colder areas. Enter your ZIP for the exact zone.
Are there insulation rebates or tax credits in Hawaii?
Yes — the federal 25C tax credit covers 30% of insulation materials (up to $1,200/year), and Hawaii's IRA HOMES/HEAR rebate programs (up to $1,600 for insulation) are administered by the state. Check the official finder for current Hawaii status.
What climate zone is Hawaii in?
Hawaii is entirely in IECC climate zone 1.