Definition for word: Thermal Bridging

Heat flow that occurs across more conductive components in an otherwise well-insulated assembly, resulting in disproportionately significant heat loss. For example, steel studs in an insulated wall dramatically reduce the overall energy performance of the wall, because of thermal bridging through the steel.

Referrence from

A thermal bridge is created when materials that are poor insulators come in contact, allowing heat to flow through the path created. Insulation around a bridge is of little help in preventing heat loss or gain due to thermal bridging; the bridging has to be eliminated, rebuilt with a reduced cross-section or with materials that have better insulating properties, or with an additional insulating component (a thermal break).

Thermal or heat bridges in building constructions are often called by the less scientific name "cold bridge".

Thermal bridges are characterized by multi-dimensional heat flow, and therefore by the fact that they cannot be adequately approximated by the one-dimensional models of calculation typically used in norms and standards for the thermal performance of buildings (U-values). Surface moisture due to condensation (typically occurring in such regions as floor-wall connections, window installations, etc.) as well as mould growth in humid environments can also be effectively prevented by means of multi-dimensional evaluation during planning and detail design.

Concrete balconies that extend the floor slab through the building envelope are a common example of thermal bridging.

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