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 Construction industry of Japan In Japan, the mainstay of infrastructure development is the construction industry, which employed 9.4 percent of the labor force in 1990 and contributed some 8.5 percent of GDP. After the two oil crises (1973 and 1979) in the 1970s, construction investment turned sluggish, and the share of construction investment in GNP decreased gradually. In 1987, however, business expanded through investor confidence, continued increase in corporate earnings, improvement of personal income, and rapid rise in land prices. The share of construction investment in GNP rose sharply, especially for more sophisticated and higher value-added private housing and private