What are Thermal Bridges?

Thermal transfer at balcony slab Thermal transfer at balcony slab

Thermal bridges are weaknesses within a building's structure where heat and/or cold is transferred at a substantially higher rate than through the surrounding envelope area.

There are basically two types of this phenomenon:

  1. geometric thermal bridges where part of the structure projects through the building envelope
  2. material thermal bridges where materials with different conductivity are used in combination

In practice, these effects often combine. A classic example of this is the balcony slab, where problems occur if the connection is not given serious consideration.

The thermograph photograph above shows that if thermal bridges at balconies are not taken care of, the balconies act as “cooling fins”; conducting the heat off the building and cooling the rooms adjacent to the balconies.

The effect of thermal bridges

  • Higher energy consumption

Due to the thermal outflow at the balcony connection, heat is drawn from EVERY ROOM resulting in a significant rise in heating costs and energy consumption.

  • Mold formation

Interior temperatures of the adjacent rooms can drop well below the dew point. This leads to condensation, deteriorates plaster and paintwork and is an ideal condition for harmful mold formation! If there is sustained exposure to condensation, the building is subject to serious deterioration.

  • Uncomfortable living space

Cold surface temperatures cause uncomfortable living space for occupants.


Schöck Isokorb® are load-bearing thermal insulation elements which forms a thermal break between the balcony and the interior floor while transferring load and maintaining full structural integrity. Also, the warmer interior temperature is maintained decreasing condensation, and preventing the formation of mold.


Schöck USA Inc.
100 Overlook Center, 2nd floor
Princeton, NJ 08540
Tel.: 855 572 4625 /
        855 5 Schöck
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