D. FOSTER Consultant Architect

In the I9th and early years of this century millions of two storey houses having single leaf one brick thick external walls were built. Many still survive giving adequate resistance to rain penetration but poor thermal insulation. Brief notes on the development of the brick/cavity/block wall devised to give improved resistance to rain and belter thermal insulation are followed by a description of the development and details of SUM {single leaf insulated masonry] for housing. Reasons are offered for its apparent rejection by the housebuilding industry and suggestions for improvement are made. Ideas about its potential use in multi-storey building and the possibility of combining it with self supporting cladding to framed structures are briefly examined.