Just some testimony from the public hearing in support of this tower...
Technically, this tower could be a lot larger than it is, considering they are merging the lots for zoning purposes. It's not an actual lot merger, so it doesn't count, but current zoning of an actual lot this size (almost 5 times the size of Vanderbilt, and 2 and a half times the size of 270 Park) would produce a humongous tower (6.7 million zsf, likely equal to 8 million gsf).
Still, even under current plans, they could build an extra 6 FAR on top of the 27 zoned by using the Transit Improvement, and Public Concourse special permits.
What the zoning allows
However, under their current plans, they will only utilize 4.27 of that 6 FAR. That comes out to
352,392 zsf of usable floor space unused. This is why the borough president and CB5 want language added that will
restrict the usage to just the 4.27 FAR amount. It was pointed out at the hearing though, that if the developers indeed wanted to use the full amount, it would trigger a completely new approval process to do so. Not likely anyone would want to do that.
What they are using