The interior floor-numbering system skips floors 13 and 25, so there are physically only 73 stories, though the top story is numbered 75.[1] The lowest 22[2][32] or 23 floors of the building are for commercial use.[4][5][33] There are luxury apartments on the remaining floors,[7][32][lower-alpha 1] as well as a mechanical story.[7] The building was designed with elaborate details. The attention to detail extended to the elevator buttons, which Jahn redesigned with three buttons to a row when Eichner found two buttons per row to be unpleasing.[8]