Software and atlases for evaluating thermal bridges (P 152)
Thermal bridges must be taken into account in the energy performance of buildings regulations of most European Member States (MS). The detailed evaluation of the linear thermal transmittance or the point thermal transmittance is one of the options to do this. Specific tools are needed to determine these values. There are two kinds of tools: numerical calculation software and thermal bridge atlases. Numerical calculation should be carried out using validated software and following rules that are usually given in a standard, which in the framework of energy performance of buildings regulations is usually the European/International standard EN ISO 10211. The first section of the paper summarizes the content of this standard and the rules to be followed for the modelling of thermal bridges. The validation test cases of this standard is described. In a second section, a survey of software tools for thermal bridge calculations is given. Finally, the available atlases used in the different MS are presented.
Air tightness requirements for high performance building envelopes (P157)
The implementation of the Energy Performance of Buildings Directive (EPBD) has caused in most of the EU Member States more severe requirements for the energy demand of buildings. In order to meet these requirements, not only buildings components with better U-values and more efficient building systems have to be used, also the ventilation losses have to be reduced. Especially for high performance buildings, which go beyond national energy performance requirements, infiltration losses become a significant factor for the energy performance. This information paper presents an overview on the existing building airtightness requirements in different European countries and compares them to the requirements for high performance buildings. According to an investigation at the end of 2007 in the ASIEPI project 7 of 14 EU Member States have minimum requirements regarding the building envelope integrated in their building codes. These are: the Czech Republic, Germany, Denmark, the Netherlands, and Great Britain. The results of airtightness measurement in high performance buildings show what can be achieved in practice.