Families who buy new homes built by private developers in Kent over the next two years could have to splash out £11,000 on installing eco-friendly gadgets in their properties – or face consistently higher fuel bills than those which are built to tough new environmental standards.

New regulations require all new homes built by housing associations to become significantly more energy efficient – and slash their carbon emissions by 25 per cent.

But the Government has given private developers until 2010 to meet the same standard.

This twin-track approach will mean that families who buy homes built by the private sector will suffer financially, according to new research by the National Housing Federation, which represents England’s housing associations.

The federation says that a family that buys a home built by the private sector up to April 2010, will have to spend £1,477 more on their gas and electricity over the first 20 years than those living in social housing. In addition, as pressure grows on people to cut emissions on a personal basis, it would cost a family in a privately-built home, around £11,000 to retrospectively install energy efficiency measures such as solar panels, improved insulation and double glazing, that will come as standard in a housing association home.

Over the next two years, private developers are expected to build around 280,000 new homes across the country. The federation estimates that the total additional cost for energy and energy-saving measures to all the households affected will be at least £3.5bn.