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A comparison of different ways to interpret energy loss for a typical, uninsulated Victorian detached home.

By % of energy: homes lose 15% through the roof, 40% through the walls, 15% through the floor, 10% through draughts, and 20% through windows.

By amount of energy lost through the fabric, measured in kWh per year as with electricity meters, based on simple heat loss calculation using SAP for typical fabric performance: 3,500 through the roof, 10,000 through the walls, 3,500 through the floor, 3,350 through draughts, and 4,325 through windows.

By the equivalent greenhouse gas emissions, measured in kilograms of CO2 equivalent,
kgCO2e, assuming a gas boiler for heating, with current building regulation emissions rates: 750 through the roof, 2,150 through the walls, 750 through the floor, 700 through draughts, and 900 through windows.

By pounds based on 10.4p/kWh for gas prices: 430 through the roof, 1,250 through the walls, 430 through the floor, 400 through draughts, and 530 through windows.