Energy Star Window ROI Calculator

Energy Star windows often unlock layered incentives. Plug in your installed cost and expected annual utility savings, then add rebates and tax credits to see the true net cost, payback period, and multi-year return on investment.

Total contractor quote for removing and installing Energy Star windows.
Estimated heating and cooling bill reduction per year.
Defaults to $1,200 for common state + utility stacks if blank.
Defaults to the 30% Energy Efficient Home Improvement Credit if blank.
Defaults to $1,200 annual cap for windows under current IRS rules.
Defaults to a 10-year analysis period when left blank.

Examples

  • $18,500 project, $1,350 annual savings, $1,200 rebate, 30% tax credit ⇒ Net cost $11,750.00, payback 8.7 years, 10-year ROI 14.9%.
  • $26,000 project, $1,900 savings, no rebate, 30% credit capped at $1,200, 15-year horizon ⇒ Net cost $24,800.00, payback 13.1 years, 15-year ROI 15.1%.

FAQ

How should I estimate annual energy savings?

Use your utility audit, blower-door test, or DOE regional averages. For colder climates, pair window U-factor improvements with heating fuel costs for a more accurate number.

Can I include DIY labor?

Yes. Add tool rentals or self-install supplies to the installed cost input so the payback reflects your true cash outlay.

What if the project spans multiple tax years?

Enter the portion of the credit you can claim in the first year and rerun the calculator for subsequent phases if you stagger the work to maximize caps.

Additional Information

  • The federal Energy Efficient Home Improvement Credit currently caps annual window claims at $1,200—adjust the cap if legislation changes.
  • Net cost subtracts rebates before applying the credit because incentives typically reduce the eligible basis for the tax form.
  • ROI horizon multiplies annual savings by the selected number of years and compares it against net cost to capture longer holding periods.

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