F. MacKenzie epub Energy Efficiency in New and Existing Buildings: Comparative Costs and CO2 Savings

This BRE Trust report considers the relative impact on UK CO2 savings targets of constructing new zero-carbon buildings as opposed to improving the energy efficiency of the existing stock. Carbon dioxide emissions from UK buildings accounted for around 40% of total UK CO2 emissions in 2006. The UK government has stated its aim to reduce greenhouse gas emissions by 80% by 2050. In order to achieve such challenging reductions in emissions, improving the energy efficiency of buildings both new and existing will clearly have a vital role to play.The Code for Sustainable Homes became operational in England in April 2007 and a Code rating for new-build homes became mandatory from 1 May 2008. The Code provides a single national standard aimed at driving continuous improvement in sustainable home building. While moving towards zero carbon for all new buildings can undoubtedly achieve a significant reduction in CO2 emissions in the future, existing buildings will form the majority of the UK s building stock for many years to come. The work presented in this report uses existing data to explore the extent to which improving the energy efficiency of the existing UK building stock would be a more cost-effective route for achieving CO2 savings than constructing new buildings to the higher levels of energy performance required to meet low- and zero-carbon targets.