If, before July 8, 2017, an application has been filed with the Department of Buildings for a development on a corner lot with a lot area of less than 5,000 square feet, located in a C5-2 District in Community District 5 of the Borough of Manhattan, the provisions established in N 190230 ZRY pertaining to calculating floor area in a tower containing residences shall not apply in the portion of such building below a height of 130 feet above the base plane, provided that the aggregate height of any floor space on stories occupied predominantly by mechanical equipment provided pursuant to paragraph (8) of the definition of floor area in Section 12-10 (DEFINITIONS), and any floor space that is or becomes unused or inaccessible within a building, pursuant to paragraph (k) of the definition of floor area in Section 12-10, does not exceed 80 feet.