A thermal bridge (sometimes referred to as thermal bridging, a cold bridge or thermal bypass) describes a situation in a building where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope.
In modern buildings, thermal bridging can occur because of poor design, or poor workmanship.
EBSNI offer advice and reducing thermal bridges in order to minimise heat loss and improve overall energy efficiency.