Home energy use is responsible for 28 percent of UK carbon dioxide emissions which contribute to climate change. Air leakage from buildings, both new build and existing, is a major cause of energy loss and increasing emissions.

The 2002 Energy White Paper gave a national target of a 20% reduction in CO₂ emissions below 1990 levels by 2010, approximately saving 1.5 million tonnes of carbon per year. 

Also in 2002, the EU issued the Energy Performance of Buildings Directive.  As a result, revised Building Regulations and supporting guidance were issued in April 2006.  These revisions included CO₂ emissions targets and air tightness testing of all new buildings.