1 Irving Place #26B overstated square footage

The 1016 is taken from the condo declaration. Zeckendorf's method of calculation was unusual, though. The measurements were taken from the inside face of the interior and exterior perimeter walls. In most condos, they're taken from the outside of the exterior walls and halfway through interior perimeter walls.

Maybe the broker estimated that difference at 83 square feet and added it on to make the unit comparable to other condos.

Duh, 84. I'm just learning to subtract.

NWT, Should all the listing in this building inflate their sq footage relative to the offering plan assuming what you are saying is true?

Why not? They're competing against other condos that used the more-usual method. Most jack it upward for no reason at all. At least this unit had something resembling a rationale.