Building Energy Efficiency Calculator
Estimate your home's energy efficiency rating
Frequently Asked Questions
A baseline consumption rate (kWh per sq meter per year) is adjusted by coefficients for building type, insulation level, heating system efficiency, and regional climate zone.
It's a simplified letter grade based on annual energy use per square meter, similar to EU energy labels — A-class buildings use the least energy, G-class the most.
Moving from no/partial insulation to above-code insulation can cut heating energy needs by 30-40%, often the single biggest efficiency improvement available for an older home.
A heat pump or geothermal system can deliver more heat energy than the electricity it consumes (COP > 1), while an old furnace loses a meaningful share of fuel energy as waste heat — this is captured as "efficiency" in the calculation.