Sir – The Government is considering the introduction of a licence of landlords who rent their housing to tenants. This is a good idea.

They should also insist that all rented accommodation meets a high standard in environmental terms — ie no rented property should be allowed on the market unless it has been insulated, centrally heated and double glazed, as well as meeting all health and safety regulations.

This will render 75 per cent of all rented property in Oxford illegal and substandard — which, of course, should not be the case in any environmentally-conscious society in the 21st century.

Matthew Baker, Oxford