It's an open and shut case

An Evening Standard survey of retailers in Oxford Street found most operate an "open-door" policy.

Environmental experts estimate each such store loses about 500kg of carbon dioxide every day - the equivalent emissions of a return flight to Malaga.

Among the shops we found with their doors open were Dorothy Perkins, Burton, H&M, Russell & Bromley and HMV.

Only a handful of larger shops - Selfridges, John Lewis and Debenhams - had their doors closed.

Today environmentalists called for an end to the practice.

Sian Berry, Green candidate for Mayor of London, said: "Shops use almost three times as much electricity per square metre as commercial offices. The open-door policy and high-powered doorway fan heaters are a big contributor to that.

"It's sad to see resources wasted on something nobody wants. It does not make anyone's life easier or more comfortable to have shops heating the air over London, but rising fuel prices and climate change do cause real hardship. Customers would really appreciate it if stores could do something as simple and sensible as keeping their doors closed, and I'm sure shareholders, who ultimately pay the electricity bills, wouldn't complain either."

Anthony Field of environmental charity WWF said: "Doors are kept open to entice people into shops but it's a waste of energy - you are just heating up the outdoors. What we would like to see is shops coming together and working towards a unified solution of a closed-door policy."

John Buckley, managing director of environmental advice company Carbon Footprint, said open doors were just part of the problem.

"The other issue is shops having their heating set too high in the winter, probably to keep their shop assistants warm," he said.

"At the same time, virtually all the shoppers have their jumpers and coats on. Turning down their heating by just one degree would save about 10 per cent of the heating bill and hence the emissions." An HMV spokesman said: "Our Oxford Street superstores were designed to have shutters across their entrance areas rather than doors.

"This was primarily to help accommodate the massive number of shoppers, including disabled customers, who expect ease of access."

Lesley Lloyd, a floor manager at the Oxford Street branch of adidas, said: "We always keep the doors open because we find it's easier for people to walk straight in. It looks much more inviting.

"We don't really think about the wasted energy. If I had to pay the bills I would think about it, but I don't."

The Carbon Trust suggested shops could install automatic or revolving doors to help to maintain the inside temperature while ensuring easy access for shoppers.