Sorry for the daft, uninformed question but we've finally got round to trying to sort out some half-decent furniture for our DS's room - which is absolutely tiny, so we're trying to figure out quite what we'll ever be able to fit in it. He's in a cotbed at present, and a 'real' single bed is a very long way off, I know, but I've no idea what sort of age an average boy is likely to need to move up out of a cot bed to a 'normal' sized one (of which the standard size seems to be about a metre wide, two metres long)...