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
Construction industry of Japan experience continued growth throughout the 1990s. These include projects for Tokyo's waterfront and other urban redevelopment, highway construction, and new or expanded airports. The growth of Japanese construction industry was actually arrested by Lost Decade economic recession and did not recover fully as in 2017. Japan's construction technology, which includes advanced earthquake-resistant designs, is among the most developed in the world. Major firms compete to improve quality control over all phases of design, management, and execution. Research and development focuses especially on energy-related facilities, such as nuclear power plants and liquid natural gas (LNG) storage tanks. The largest firms are