well, room dimensions have changed with time, and high ceilings (at least in the south) had a lot to do with keeping a room cooler in the summer... same thing with doors that don't go all the way up to that high ceiling, the hot air doesn't move from room to room...
rooms used to have a slightly bigger sqft footprint to accomodate armoirs and chiffarobes like syracusa described, as opposed to having closets. bigger houses were made even bigger still by the need to have servent quarters/entrances/stairwells, etc...
all in all i find the history of residential architecture too darn interesting and almost as addictive as office supplies
