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
Building and Construction Authority Building and Construction Authority The Building and Construction Authority (Abbreviation: BCA; ) is a statutory board under the Ministry of National Development of the Singapore Government. It was established on 1 April 1999 through the merger of the Construction Industry Development Board and the Building Control Division of the former Public Works Department. The primary role of BCA is to develop and regulate Singapore's building and construction industry. BCA ensures that buildings in Singapore are designed, constructed and maintained to high standards of safety through its building regulatory system. In October 2004, BCA issued a window retrofitting order, requiring aluminium