heat loses

Transmission heat loss takes place from the fabric of a building through the walls, floor, roof, glazing and also through air leakage. Solar gain through glazing can contribute to overheating in summer and can lead to the need for mechanical cooling.

Fabric loss is approximately 80% of overall heat loss, with the rest attributed to infiltration and ventilation losses.

Low energy design can reduce heat loss by up to 50%, using a combination of increased wall insulation, better glazing U-values, ventilation control, shading in summer and optimising solar heat gains in winter, and improved control of heating and cooling systems.

What should I do?

For refurbishment projects improving the fabric is critical for sustainable design. Great care should be taken to select the most appropriate fabric improvements for the buildings age and construction type.

WLGA - CLILC Llywodraeth Cynulliad Cymru / Welsh Assembly Government