We're moving house and looking to convert the detached garage 17x13 into a home cinema. The garage has a corrugated roof and I am expecting to replace this with a proper piched tiled roof. I will have to extend it slightly because I want to put a loo in there. It doesn't currently have running water or drainage and this is something which I know will cost. But it's a way down from the house and the trip to and from the house for a pee would be too inconvenient. Are there any regulations which stipulate that there has to be a room between the loo and the main room? Also as far as heating is concerned, I don't want the room to be cold an unwelcoming in the winter. Obviously an electric radiator is a cheap and easy solution. Would a proper heating system and radiator be OTT? Expensive? TIA.