Thermal bridges

Heat bridge calculations

Reduce weak points in the building envelope and use higher subsidies!

Heat takes the path of least resistance, so in very simplified terms, thermal bridges are "energy loopholes", which have a higher thermal conductivity than the rest of the building envelope.

Typical representatives of this phenomenon are, among others, ceiling supports and window connections as constructional thermal bridges and building corners as geometrical thermal bridges.

The ever-increasing demands on the building envelope mean that it is necessary to take a close look at these details in order to meet the minimum legal requirements or, if necessary, to achieve a certain level of support. Similarly, detailed planning can also enable the most economical insulation thickness possible. Especially in the case of high-efficiency houses, the planning of details with low thermal bridging is an integral part of an energy-saving and damage-free overall concept.

The EnEV permits three variants for taking into account the additional heat losses due to thermal bridges:

Thermal bridges can be taken into account without concrete proof with a flat-rate surcharge of 0.1 W/(m² K) over the entire building envelope.
The flat-rate surcharge can be halved to 0.05 W/(m² K) as soon as the implementation of Supplement 2 of DIN 4108 is confirmed within the scope of a so-called proof of equivalence.
As an alternative to the flat-rate surcharges, the existing thermal bridges can also be taken into account individually by means of a detailed calculation.
The Bode Planning Office team will be happy to help you with the topic of thermal bridges.

Sebastian Elak B.Eng.
Building Physics