[holding answer 14 March 2007]: Enforcement of higher standards for the energy efficiency of homes is the responsibility of Department for Communities and Local Government (DCLG). DEFRA has been working closely with DCLG to secure greater energy efficiency of new and existing homes through amendments to Part L of the Building Regulations. DEFRA supports the recent amendment to Part L, which will lead to an increase in the energy efficiency of new homes by approximately 20 per cent. compared with those built to the 2002 Regulations. DEFRA also supports the commitment that all new homes will be zero carbon by 2016, introduced through a timetable of phased improvements.