My home is too small and I cant afford a bigger home! What can I do?

I live in a one bedroom house in Buckinghamshire and share the bedroom with my partner and our son. We have just had a new baby girl and now have our double bed and two cots in the room. The drawers have been moved to the landing as we just have no floor space, and most of our cloths have no home as we do not have room for storage. We are on a housing list but they are saying that our one bed house is big enough, as our son only counts as 0.5 of a person untill he is 8, and our daughter doesn't count at all, till she is 1 and then she will be 0.5 of a person. I have a job but am the only one working as my partner is at home with our children, so we do not have the funds to rent a bigger home! Its really getting me down. Is there anything I can do???