All you need to know about thermal bridging

Why is thermal bridging an important consideration? Put simply; it will cost you more money to heat the property.

A thermal bridge is an example of heat transfer through conduction. It is also referred to as a ‘cold bridge’. Thermal bridges in construction are the ‘leaky points’ of a building where heat escapes. The speed of heat loss depends on the materials’ thermal conductivity and the difference in temperature on either side of the thermal bridge.

The heat loss associated with these thermal bridges is expressed as a linear thermal transmittance (Ψ-value) – pronounced as ‘psi-value’.

The Conservation of fuel and power: Approved Document L (the building regulation in England setting standards for the energy performance of new and existing buildings) states that ‘The building fabric should be constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps within the various elements, at the joints between elements and at the edges of elements such as those around window and door openings.’