floorplate thickness
The distance between the upper and lower surfaces of a structural floorplate, not counting veneers or lowered ceilings.
The floorplate thickness for any building is the median vertical distance between the upper surface and the lower surface of a structural floorplate in that building, not counting the basement floor or the roof. The thickness does not include any dropped ceiling or floor veneer.
This measurement is always less than or equal to the finished floor thickness.
The value is a median across the whole object and not a figure taken from one place. A tower normally has thicker walls low down than high up, so a number read off a single detail drawing answers a different question than this field asks.
Where a building has two clearly different constructions, such as a podium and a tower, each is described on its own record rather than averaged into one value.