Sir – On a cold February day I had some time to spend in central Oxford without any necessary errands to be done. I decided not to go into any shop which left a front door open to the outside, since this increases energy use for heating and contributes to climate change. This decision limited my choice considerably.

One beneficiary was the ‘New Statesman’, since Smith’s had their doors closed so I went in and browsed the magazines and bought a copy. Also allowing their door to close was Sainsbury’s, so I could buy some of their tea, which I like.

Tesco’s automatic door never seemed to close, though to be fair there did seem to be people passing in and out regularly so maybe it didn’t have a chance. Waterstones door was open.

I made a special trip to Blackwell’s to check whether they, too, were out of bounds for the day. But their door was closed and a second door put out of use to keep it warm inside (the sign said). Good for them.

If I had had to stay around any longer, it is their coffee I would have drunk, as Debenham’s seemed to feel that they would be disadvantaged if they did not leave one door to their downstairs entrance area open, and Pret à Manger also had an open front door.

Since closing the door would save them money, perhaps more shops will be willing to join the energy-saving minority, until it becomes the majority.

Jeanne Warren, Garsington