How to use this estimate
- Simple payback ignores future energy inflation, financing, comfort, moisture control, and resale value.
- Air sealing is often paired with insulation because uncontrolled leakage can dominate heat flow.
- Resolve roof leaks, unsafe wiring, and combustion-safety issues before covering an attic.
Transparent method
We expose the planning formula so you can challenge it and replace assumptions with local evidence.
annual utility cost × HVAC share × expected HVAC reductionWhat this calculator cannot see
- Savings vary by climate, starting insulation, air leakage, heating fuel, and workmanship.
- A qualified energy audit gives a better load-reduction estimate.
Professional verification
Use this result to prepare questions and compare scenarios. Final equipment selection, electrical work, refrigerant work, combustion, duct design, and permitting should be handled by qualified professionals following local codes and manufacturer instructions.