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
Trade Unions International of Building, Wood, Building Materials and Allied Industries Trade Unions International of Building, Wood, Building Materials and Allied Industries The Trade Unions International of Building, Wood, Building Materials and Industries, also known as the Trade Unions International of Construction, Wood, Building Materials and Industries, or by its French acronym UITBB ("Union internationale des syndicats des travailleurs du bâtiment, du bois et des matériaux de construction") is a Trade Union International affiliated with the World Federation of Trade Unions. The UITBB was founded at a conference in Milan in 14–16 July 1949. The highest organization is the Conference which meets every 4 years. Between conferences, the union is run