buildings and layouts

So my son spent a half day at a Sony computer lab, and, when I asked him, he reported he was on the 4th floor. Somehow the fact that there was a big elevator figured as importantly in his retelling as the fact that he spent time on computers. This from the boy who has to know about how many staircases there are in any new building, whether there is a ground floor or basement. Anyway, he was happy about the trip.