bibbitybobbityhat - you siad what I was thinking. There was no way we were over crowded when I was a child, and was sharing with my brother.
I'm a bit bemused by this over corwding thing. We could have bought a 4 bed house in a crappy area, and all of my DC's would have had thier own (all be it tiny) room. We chose to buy a large(ish) 3 bed in a lovely area. If my boys were made to share a room there would be a murder before too long (we did try it when we moved in) so that left the younger two to share. (They're close in age, so still play with the same toys and the room is very large, as it already part of an extension.)
I find the thought that we will soon be technically be over crownded a bit odd...nobody would think we are poor, we have a big garden, and lots of living space, but maybe I should start panicing.