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 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