Alaska Insulation Requirements

Zone 7 (Very Cold) Requirements in Alaska

The following R-values are recommended by the DOE for buildings in the Zone 7 (Very Cold) portions of Alaska. Zone 7 has approximately 10,000 heating degree days and 300 cooling degree days annually.

Zone 8 (Subarctic) Requirements in Alaska

The following R-values are recommended by the DOE for buildings in the Zone 8 (Subarctic) portions of Alaska. Zone 8 has approximately 14,000 heating degree days and 100 cooling degree days annually.

Alaska Insulation Overview

Alaska is unique in containing both Zone 7 and Zone 8, the two coldest climate zones in the country. The extreme cold, high energy costs, and remote location of many communities make insulation one of the most critical building components in the state. Fairbanks and the interior fall in Zone 8 with heating degree days exceeding 14,000, while Anchorage and coastal areas are in Zone 7. The Alaska Housing Finance Corporation provides energy audit and weatherization assistance programs that help homeowners identify insulation improvements. Superinsulated construction with R-40 or higher wall assemblies and R-60 or higher attic insulation is standard practice for new construction. The investment in high R-value insulation has the fastest payback period of any state due to extreme heating costs.

Key Insulation Tips for Alaska

Regardless of which climate zone you are in within Alaska, the following insulation best practices apply to every project. Start with the attic, which is typically the easiest and most cost-effective insulation upgrade. Before adding attic insulation, air seal all penetrations through the attic floor to prevent warm air from leaking into the attic space. This includes sealing around light fixtures, plumbing vents, electrical wiring, HVAC ducts, and the top plates of interior partition walls.

For existing homes, consider having an energy audit performed before deciding on insulation improvements. A blower door test will identify the specific air leakage paths in your home, and an infrared camera scan will reveal areas of missing or inadequate insulation. Many utility companies in Alaska offer free or subsidized energy audits, and the investment in professional diagnostics ensures that your insulation dollars are spent where they will have the greatest impact. The federal government offers tax credits for insulation improvements through the Inflation Reduction Act, and state and utility programs may provide additional incentives.

When hiring a contractor for insulation work in Alaska, verify that they are properly licensed and insured, and ask for references from similar projects. For spray foam insulation, the contractor should be certified by the manufacturer of the specific foam product being used. For blown-in insulation, ask about the installed density and coverage area to verify that you are getting the rated R-value. Request a certificate of insulation showing the installed R-value, coverage area, product name, and manufacturer, which is required by most building codes and valuable for future property transactions.

Climate Zones in Alaska

Other States

Browse insulation requirements for other states.