I am doing a project and have been wondering this same thing for a while now. I am pretty young though and I just want to get a couple things straight. Looking at the picture below (taken by harryc) if the concrete slabs between floors are say, 9" thick, then does that make the area in between the slabs the entire living (or office, or whatever) space, or are other things added in between? (Where do the air vents and all that go?)
Sorry, this sounds confusing.
