My first RAF quarter, at Halton, had a bonus door in the lounge. It was supposed to have been a window but somebody copied the plans down wrong and they built an estate's worth. The extra draught was refreshing helped by the fact that nobody knew the state of the back boiler behind the fire so, rather than find out, they banned having a fire. Twenty years later I was back at Halton and spare doors had been turned into windows and a piece of hardboard had been fixed into the hearth - so there was no way were were going to have a fire.