A £15 million project to build hundreds of new zero-carbon homes has fallen flat after only 15 qualified in the first year, The Times has learnt.

Gordon Brown’s scheme, which he championed in his last Pre-Budget Report as Chancellor, has failed because the Government’s specification for a zero-carbon home is not practical, the building industry says.

In November 2006 Mr Brown said he would waive stamp duty for new zero-carbon houses, giving buyers savings of about £15,000. This was extended to flats and maisonettes in last year’s Budget.

The figures, disclosed by Ian Pearson, the Treasury Minister, raise wider questions about policy on zero-carbon homes. Low-carbon campaigners such as Chris Goodall have pointed out that they are extremely costly to build. A better, cheaper alternative, he suggests, would be subsidies to improve the air-tightness of existing buildings.

Building companies say the failure to design a workable zero-carbon scheme calls into question the Government’s ambition that all new homes should be constructed to a zero-carbon standard by 2016.

Homes designed for zero net carbon emissions must include some form of power generation to offset the use of electricity, gas and other utilities. This would typically mean a wind turbine or solar panels. However, the UK Green Building Council, which represents the green building industry, says microgeneration is not practical in the majority of cases.

The Callcutt review of housing, commissioned by the Government, said the 2016 target for all new homes to be zero-carbon was achievable if they agreed a clear definition of what such a home was. Paul King, the chief executive of the UK Green Building Council, said: “As Government was warned in late 2007, the definition of zero-carbon is at present too restrictive. This is not about dumbing down the concept of zero-carbon or the level of our ambition – far from it – it is about recog-nising that developers should be able to achieve the same level of carbon savings but through more flexible means.”

Grant Shapps, the Tory housing spokesman, said: “This was announced at the same time as eco-towns, and both initiatives have turned out to be spectacular failures. We said at the time that Gordon Brown was more interested in grabbing eco-headlines than doing anything real for the environment. The latest revelation that just 15 homes have qualified for the zero-carbon tax break demonstrates that this is an eco-con.”

A Treasury spokesman said: “Stamp duty land tax relief for zero-carbon homes was always expected to only be picked up in small numbers in the first few years. The aim is to kick-start a market for new, highly efficient homes as few exist.”

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