Housebuilders will not be able to build zero-carbon homes without a major change in government energy policy, housebuilders have told ministers, writes Joey Gardiner.

Building has learned that Stewart Baseley, chair of the Home Builders Federation (HBF), has written privately to Caroline Flint, the housing minister, to say builders will not on their own be able to reach zero-carbon targets.

The move comes as the government’s approach to its 2016 zero-carbon target is coming under pressure, with speculation growing that it will water down proposals that commit it to ensuring that new homes are “net zero carbon” by 2016.

Baseley argues that the government should rely on energy policy to reach level six, the zero-carbon level of the Code for Sustainable Homes. This requires that renewable energy be used to power home appliances. Builders alone can reach only levels three to four through more efficient buildings, he maintains, saying there should be a presumption that energy would be produced off-site “unless it is economically viable to do so on-site”.

John Slaughter, director of external affairs for the HBF, denied Baseley’s letter marked a withdrawal of support for the zero-carbon agenda.

He said: “This isn’t a change of direction, it is part of an ongoing process of defining zero carbon. It was a private contribution to the debate at the 2016 taskforce.”

This isn’t a change of direction, it is part of a process of defining zero carbon

John Slaughter, hbf

He added that if zero carbon were achieved by loading expense on builders then it would make sites less viable and they would build fewer homes.

The communities department’s line is that zero carbon can be reached using the code, Building Regulations and the planning system, without recourse to energy policy.

An industry source said: “There are discussions within government about what a likely alternative to the code might be, or at least how it could be made a hell of a lot simpler.”

The government is due to launch a consultation on the definition of zero carbon in the next few months. The communities department said it would “continue to engage with the Zero Carbon Taskforce to ensure the industry is fully involved.”