Heat Loss / Boiler Size CalculatorQuick whole-house heat loss for boiler or heat pump sizing.Heated volume (m³)Building standardPre-1990 (50 W/m³)Modern (35 W/m³)Passivhaus (20 W/m³)ResultRequired output10.78 kWSuggested boiler12 kW combiEnjoy Calcurly.com ad-free — go Premium