R-value (insulation) as ASHRAE 90.1 and the IECC prescribe U-values. However, R-value is widely used in practice to describe the thermal resistance of insulation products, layers, and most other parts of the building enclosure (walls, floors, roofs). Other areas of the world more commonly use U-value/U-factor for elements of the entire building enclosure including windows, doors, walls, roof, and ground slabs. The SI (metric) unit of R-value is whereas the I-P (inch-pound) unit is For R-values there is no difference between US customary units and imperial units, so the same I-P unit is used in both. Some sources use ″RSI″ when referring
Development Fund of the Swedish Construction Industry Development Fund of the Swedish Construction Industry Employers and employees founded the Development Fund of the Swedish Construction Industry (Swedish: Svenska Byggbranschens Utvecklingsfond, SBUF) jointly in 1983. SBUF is the construction industry's organisation for research and development with approximately 5,000 affiliated companies in Sweden. SBUF aims to promote development in the building process to create more businesslike conditions for contractors enabling them to make use of research and conduct development work. SBUF aims to promote development in the building process to create more businesslike conditions for contractors enabling them to make use of research and conduct development work. SBUF operates