Table of Contents
The overall heat transfer coefficient or U-value
In the PHPP worksheet U-Values of all building elements of the building envelope, or, in other words, all building elements through which heat is lost, are listed with their assemblies and respective thermal conductivity values. The calculation strictly follows EN standard 6946 (background information on the Passipedia pages ).
Entering the thermal conductivity in the PHPP
Passive House Certification procedure
As per the certification criteria for the certification of Passive Houses, documents verifying the thermal conductivity (lambda value) of each insulation material and building component must be submitted. For Passive Houses in Germany, the German 'Bemessungswert' is to be used in accordance with DIN V 4108-4. For the certification of Passive Houses in all other countries, the lambda value determined as defined by the respective national norms regulating the calculation of a building’s energy balance must be used. In the absence of a national norm, a thermal conductivity value that has been checked and confirmed by an independent third party can be applied. As such, the lambda value stated on the CE label, for example, may be used for the PHPP. If Passive House suitable components as certified by PHI were used, however, the lambda value stated in the PHI certificate must be given, irrespective of the country of construction.