Thermal bridge

A thermal bridge is a place in a building envelope where a variation in thermal resistance occurs, such as where two elements meet (a wall and a slab) or where there is a change of materials (glass and concrete on a façade). Thermal bridges are points where the building's thermal insulation is less effective. Reducing thermal bridges thus contributes directly to improving a building's energy performance. In a poorly insulated house, for example, thermal bridges can account for 20% of heat loss (source: Ademe).