The height of all buildings or other structures shall be measured from the base plane. The provisions of Section 101-221 (Permitted Obstructions) shall apply to all buildings within the Special Downtown Brooklyn District.

In R7-1, C5-4, C6-1, C6-4 and C6-9 Districts, except C6-1A Districts, the underlying height and setback regulations shall not apply. In lieu thereof, all buildings or other structures shall comply with the provisions of Section 101-222 (Standard height and setback regulations) or, as an option where applicable, Section 101-223 (Tower regulations). Buildings or other structures within the Flatbush Avenue Extension and Schermerhorn Street Height Limitation Areas shall comply with the provisions of Section 101-30 (SPECIAL PROVISIONS WITHIN HEIGHT LIMITATION AREAS). However, the underlying height and setback regulations shall apply to any Quality Housing building, except that Quality Housing height and setback regulations shall not be applicable within any R7-1 District mapped within a C2-4 District.