[STR]

55,000 is gross sqft. 63,000 is rentable sqft. I'm not sure what the distinction is in New York real estate law, but I'd guess that GSF is the floor plate, including shared amenities (toilets, hallways) and utilities (voids for elevator shafts, electrical closets), while RSF is GSF plus a proportional share of the mechanical floors, which is why it's bigger than the actual floor plate. I've got fairly recent floor diagrams of this building, so I know what the physical dimensions are with enough accuracy. I don't have any elevations, so I cannot shed much light on the change in that number.