The floorplate-to-flloorplate (floor-to-floor) height is the median interval between the top of one floorplate and the top of the next successive floorplate.

If a building has an even number of irregularly spaced floors and a median cannot be obtained, then the average of the two measurements in the middle of the range is used. Any floorplate of variable height should be assigned its median level.

Three fields measure the same story and give three descending numbers. Floorplate to floorplate is the full story including the slab, floor to ceiling is what is left inside the finished room, and the indoor clearance is what remains once ducts and lighting hang below it. A value in the wrong field is out by the thickness of a slab or a ceiling void.

A building rarely has one value throughout. The lobby and the mechanical levels differ from the typical office story, and this field describes the typical one unless the record says otherwise.