If a bedroom has been advertised as a double, it could mean anything you can fit a 4'6" wide bed into and still have about 60cms space around the perimeter!!! Basically and honestly, any bedroom you can fit 2 single beds or a double bed+ and still have room for the bedroom furniture without banging into it everytime you make the bed. If you can't do this, it's a single or a large single bedroom. It really is open to interpretation.