This Digest gives a method for assessing U-values of light steel-frame constructions. The method has been validated using the procedures in BS EN ISO 10211-1 and enables U-values to be calculated by means of a simplified method. It is similar to the one given in BS EN ISO 6946 but with some important differences. It can
easily be incorporated into software tools used by designers, builders and enforcers of the Building Regulations wishing to calculate U-values of light steel-frame constructions. The method was developed jointly by BRE and The Steel Construction Institute. This Digest supports the 2002 editions of Approved Documents L1 and L2 for the Conservation of Fuel and Power. It is addressed to designers and others concerned with energy efficiency in buildings and assumes that they are familiar with the procedure for calculating U-values given in BS EN ISO 6946. 12 pages.