Green Building Energy Calculator
Estimate annual energy savings and payback periods from green building upgrades.
Compare LED lighting, insulation, solar, and HVAC by home size and bill.
Green building upgrades reduce energy consumption, lower bills, and reduce carbon emissions. The payback period — how long before the savings cover the upfront cost — is the key metric for deciding which upgrades make financial sense.
This calculator estimates savings for five common upgrades based on US Department of Energy and ENERGY STAR data:
LED lighting typically saves 8-10% of a home’s total energy bill. The technology is mature and installation is trivial. Most homes still running incandescent or older fluorescent bulbs recoup the LED cost in under three years.
Smart thermostats save roughly 10-12% on heating and cooling, which is the largest share of most home energy budgets. The savings are highest in cold-climate homes where heating runs for months at a time.
Additional insulation (attic and walls) saves 15-20% on heating and cooling. This varies enormously by existing insulation quality and climate — a poorly insulated attic in Minnesota can drop heating costs by a third with a full batt installation.
Energy-efficient windows reduce heating and cooling loads by 10-15%. They also improve comfort (less cold drafts in winter) in ways that do not show up in energy bills. The payback is longer than insulation — typically 8-15 years — but the comfort benefit is immediate.
Heat pump HVAC replaces gas or electric-resistance heating with a system that moves heat rather than generating it. Modern heat pumps can deliver 3-4 units of heat energy per unit of electricity consumed. In cold climates with gas heating, payback depends heavily on electricity versus gas prices in your area.
Installation cost estimates are scaled to your home size using industry averages. Actual quotes will vary by region and contractor.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.