We just did this on Saturday! My oldest has been sharing a room with her 2 sisters and really needed some personal space. So we moved the 3 oldest boys from their room and put them into the dining room ( had to run to Lowes and buy 2 doors, but it works nicely) and we moved my DD into thier room. Then we moved our dining room table to the living room and moved the books shelves and my desk from the school room into the new dinning room, creating a nice sized, new school room. Next we moved the living room into the old school room/family room. Confused yet? :D
So we went from a 4 bedroom house to a 5 bedroom with a larger school room all in days ( very hard) work.