Hi all, This is probably going to sound strange but hopefully someone may be able to offer some kind of explanation or advice. We live in a 4 bed detached house which is 4 years old. We have developed a rather unusual smell in one bedroom on the middle floor. We can only liken the smell to that of Stale Cigarette Smoke. The thing is, no-one in the house smokes, nor has anyone smoked in the house...ever. This smell only affects this room and disappears if we open the window and ventilate the room. We have removed everything from the room and washed the curtains and carpet and cannot smell anything on the floor, walls or ceiling. Yet if we close the door and window at night, the stale cigarette smell is back again by the morning. There is'nt any mold growing on the walls nor can we feel any damp patches anywhere. We are also pretty sure that the smell is not coming in from outside as it occurs regardless of weather conditions or wind direction. Has anyone ever experienced this sort of problem before? Many Thanks for reading. Stu