Choose aluminium doors and windows that help you save energy

If you are looking for doors and windows for your new house or replacement ones during renovation – or to obtain tax credits for energy efficiency – you should bear in mind their heat class, or window heat transfer value (U_w). Heat transfer indicates the rate of amount of heat passing through an element of 1 m₂ with a temperature difference of 1 °C between indoors and outdoors (unit of measurement: W/m²K). So the lower the value, the better insulated the door or window.