A Devon poultry farmer has become only the second in the UK to install under-floor heating in his sheds, slashing his energy bill by up to half.

Stuart Cole built the new free-range sheds at Menchine Farm, Witheridge, where he rears free-range chicken for 2 Sisters Willand. The two new sheds, finished in November, house 5750 birds each, bringing the whole farm total to 34,500 birds.

"Keeping the chicks and the litter they're on warm is crucial to successful poultry rearing," said Mr Cole. "Within a few months of building the other (four conventionally heated) sheds I figured there must be a better way than heating the air above the chicks and then using yet more energy to push the warmth down to their level. But at that time the technology to do it differently just wasn't available."

Day-old chicks need a temperature of 33C at floor level to survive. Traditional air heaters heat the air to at least 40C, to make up for the warmth lost before it reaches floor level. Mr Cole's new under-floor system maintains an optimum temperature right where the chicks are, reducing in a controlled manner as they grow.

The system cost an extra £9000 per house to install, but with energy savings of about 50% it would pay for itself within five years, he said. "It was a bit of a learning curve to start with as we usually put quite a lot of bedding in to keep the chicks off the cold floor - I put too much in, which kept all the heat in."

The new sheds also have polycarbonate windows, representing 10% of the total floor area - significantly higher than the 3% required by the RSPCA's Freedom Food standards.

"The windows give a completely different feeling when you go into the sheds," said Mr Cole. The new houses were also coping well with the cold weather, staying much drier and more pleasant than the conventional sheds.

Andrew Maunder, commercial director at 2 Sisters Willand, said he was very proud of Mr Cole's initiative. "He's blazing a trail we hope other farmers will follow."