Attic Insulation Savings Calculator

Heat loss through the attic is proportional to 1/R. Going from R-19 to R-49 cuts attic loss by about 61% — but only the attic portion of your bill, not the whole bill.

For most homes the attic is 15-25% of total heat loss. Combine this with air sealing the attic floor for the biggest impact — air leaks bypass insulation entirely.

• Air seal first: top plates, can-light penetrations, attic hatch, plumbing chases.
• Blown-in cellulose is usually the cheapest way to add R-value (DIY rental possible).
• Don't compress existing insulation — add new layers loosely on top.
• Insulate and weatherstrip the attic hatch — it's a giant uninsulated hole otherwise.
• Check state and utility rebates — the federal 25C tax credit ended Dec 31, 2025.

Results are estimates based on typical conditions. Actual costs vary by climate, utility rates, equipment efficiency, and home characteristics. Use them as a starting point — for precise figures consult a qualified energy auditor or your utility company. Estimates are not a guarantee, and any work you do on your home is at your own risk — we are not liable for installation errors or property damage. Air sealing a home with gas, oil, propane, or wood-burning appliances can cause backdrafting and carbon monoxide risk — get a combustion safety test and keep CO alarms working. See our Disclaimer.