The Code allows potential buyers to see how environmentally sustainable their homes are. The Government hopes this will encourage developers to build greener homes.

However the Federation, which represents housing associations, has said the only way to guarantee high environmental standards across the board is to compel all house builders to meet Level 3 of the Code from next year.
 
The Code for Sustainable Homes is initially only mandatory for publicly funded homes, such as those built by housing associations.
 
Housing associations will have to meet Level 3 of the Code from April 2008. For other house builders, however, the Code will remain voluntary until 2010 and by that time associations will have moved up the next rungs of the Code timetable.
 
The Federation has called for private developers to be compelled to meet the same standards and timetable as housing associations.
 
David Orr, chief executive of the National Housing Federation, said:

"There is little point in asking builders to rate themselves against the Code for Sustainable Homes if they are not going to be compelled to meet it.
 
"We will see an abundance of homes rated at Level 0 and Level 1, which will do nothing to stimulate greener building. It will simply confuse homebuyers.
 
"A voluntary code lacks teeth. Currently, housing associations are being made to research and invest in new building technologies on behalf of private developers. This is not good enough. We need an industry-wide push towards greener building, kick started by the Government.

He added:
 
"We will have two supply chains, operating at staggered times. But by applying the same standards and timetable across the board, the Government could bring down construction costs - and, more importantly, reduce the environmental impact of new homes and slash household bills to boot."