It's not on the table for us but really wouldn't change anything (except my career ). We have two boys in one room, one in another and our DD in another. All three rooms have bunk beds therefore we have an empty bed in a boy room and an empty bed in the girl room already. I don't think I could do it in a smaller than 4 bedroom house though. I also have an 8 seater car with room for extra kids. So honestly I doubt 4 to 5 would be a big deal. I suspect 3 to 4 would be a bigger change as it involves an upgrade from a regular to a plus size car, but as I didn't personally experience that change I couldn't say for sure