EN ISO 6946 : Building components and building elements - Thermal resistance and thermal transmittance - Calculation methods (ISO 6946:2017, Corrected version 2021-12).

This standard specifies a method for calculating the thermal resistance and thermal transmittance of building components and elements. It excludes doors, windows and other glazed elements, curtain walling, components involving heat transfer to the ground, and components through which the building’s ventilation air flows. The calculation is based on the appropriate design thermal conductivities or design thermal resistances of the materials and products concerned. The method applies to components and elements consisting of thermally homogeneous layers, which may include air layers. An approximate method is also provided for elements containing thermally heterogeneous layers. It accounts for metal fasteners by means of the correction term specified in Annex F. Other configurations in which metal penetrates the insulation are excluded. Table 1 in the Introduction shows the position of this standard within the EPB series and the modular structure defined in ISO 52000-1.