R-value (insulation) contain no trapped CFCs or HFCs (e.g., half-pound low density foams). On certain brands, twenty-year tests have shown no shrinkage or reduction in insulating value. This has led to controversy as how to rate the insulation of these products. Many manufacturers will rate the R-value at the time of manufacture; critics argue that a more fair assessment would be its settled value. The foam industry adopted the LTTR (Long-Term Thermal Resistance) method, which rates the R-value based on a 15-year weighted average. However, the LTTR effectively provides only an eight-year aged R-value, short in the scale of a building that
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