Passive house

A passive house is defined as a building whose annual heating demand does not exceed 15 kilowatt hours per square metre. To achieve this, wall surfaces must have a U-value (thermal transmittance coefficient) of no more than 0.15 W/(m²K). For window surfaces, a U-value of 0.8 must not be exceeded. In addition, achieving the passive house standard requires the installation of a ventilation system with heat recovery, as well as various other insulation-related and structural or architectural measures.