The UK’s building trade body has bashed laws which could mean homeowners have to spend thousands of pounds extra on green home improvements when they extend their homes.

The Federation of Master Builders (FMB) warns plans from the Department of Communities and Local Government (DCLG) will be “impractical, unpopular and counterproductive”.

Changes to the Government’s “Part L” building regulations will mean homes and businesses may have to boost their property’s insulation or efficiency measures if they want to add any home improvements.

But Brian Berry, Chief Executive of the FMB said: “There is an urgent need to improve the energy efficiency of our existing homes but people should be encouraged and not forced to take action as the current proposals will only backfire on the Government.”

Many builders are apparently unconvinced by the Government plans.

Mr Berry added: “A survey of our members reveals that 70% of FMB building companies do not believe that the Government’s proposals are technically, functionally or economically feasible to implement for most domestic extension projects.”

Around three-quarters of builders also believe home owners would carry out less work as a result of the proposals, or even turn to “cowboy builders”, he said.

The Government claims it will be a huge support for the Green Deal.

However a spokesperson for FMB told ELN today: “It is fact it is the opposite. It is an admission that they have failed to make Green Deal sufficiently attractive so they are going to use regulation to force people to have it whether they like it or not. If they want to support Green Deal, they need to introduce meaningful incentives.”