The document discusses issues with building efficiency in the UK construction industry and proposes solutions to improve building performance. It notes that UK buildings often use significantly more energy than predicted and fail to meet air infiltration standards. Thermal bridging, insulation levels, and air leakage are identified as key areas of non-compliance. The solution is outlined as focusing on building envelope efficiency through high insulation values, low thermal bridging, and air tightness, which can reduce heating and cooling loads by 80%. Renewables and technology provide the remaining 20% of efficiency.