Building Regulations / Standards set the levels of thermal insulation required when carrying out building work, either for new build or refurbishment projects. These are expressed as a U-value which needs to be achieved. The required U-value will depend on the location of the project (England, Scotland or Wales), type of building (domestic or non-domestic) and the application (floor, wall or roof).
The tables below show the suggested U-values in England, Wales and Scotland. Note the distinction between the domestic and non-domestic columns. Below that, there are more detailed guides to the thermal insulation parts of Building Regulations / Standards.