Thermal bridging refers to the conduction of heat through a building frame (e.g. steel or timber studs in the walls and roofs), allowing heat to bypass an otherwise effective insulation system. Steel framing is particularly prone to this due to its high conductivity.
A frame can constitute up to 15% of a roof, wall, or floor surface area. This means that you are potentially losing insulation performance through the frames, therefore making your appliances work harder to maintain a comfortable temperature.
To learn more about overcoming the effect of thermal bridging, visit our article about continuous insulation.