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
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