It seems that the site for this project is located at 373-375 Broadway (aka 9 Franklin Place) and 369-371 Broadway (aka 3-5 Franklin Place).
This block -- bounded by Broadway / White St. / Franklin Place / Franklin St. -- is a non-Landmarked block. However, it is surrounded on the west, north and east by the Tribeca West Historic District (see LPC Map HERE ).
The existing building at 373-375 Broadway is a 6-story building which appears to have cast-iron facade that sits on a plot 150' x 50':
The building to the south (371 Broadway; aka 5 Franklin Place) is a 5-story / 50' building on a 25' x 150' plot with a lousy looking 60's facade (as seen at the far left in the photo above).
The building to the south of that (369 Broadway; aka 3 Franklin Place) is a 5-story building on a 25' x 150' plot.
The building to the north (377-379 Broadway) is a 12-story / 145' commercial condo.
NYC Department of Finance records show that a transfer of the 373-375 property was recorded on 11.13.2006; on that same date a transfer was recorded for 369-371 Broadway (amount recorded on that date: $3,072,333.00).
The 373-375 property was recorded in the name of Ascendance Development LLC. The 369-371 property was recorded in the name of Sleepy Hudson LLC.
Google search for "Ascendance Development" turned up an ad at nylawyer.com:
Hopefully the plan here is renovate the cast iron building at 373-375 and use the air rights from that plot to build the new 21-story building on the site of 369-371.NOTICE OF FORMATION of ASCENDANCE DEVELOPMENT, LLC,
a domestic Limited Liability Company (LLC). Articles of Organization filed with Secretary of State on 6/9/05. NY Office location: NEW YORK County. Secretary of State is designated as agent upon whom process against the LLC may be served. Secretary of State shall mail a copy of any process against the LLC served upon him/her to C/O LEO TSIMMER, C/O SLEEPY HUDSON, LLC 261 MADISON AVE STE 1504 NEW YORK, NY 10016. PURPOSE: To engage in any lawful act or activity. 645190 f23-Th m30
That would save the 5-story existing building -- and would also maintain a buffer between the existing 12-story building to the north and this new "tower".