The provisions of this Section, inclusive, shall apply to the ground floor level street frontage of a building along a Tier C street frontage.

The provisions for Tier B street frontages, as set forth in Section 32-32, inclusive, shall apply, except that the regulations of Section 32-322 shall not be permitted as an alternative to those of Section 32-321, and the ground floor level use limitations set forth in paragraph (a) of Section 32-321 shall be modified as follows:

1. in addition to dwelling units, ancillary residential uses, other than lobbies and associated amenities, shall not be permitted on the ground floor level within the minimum qualifying depth;
2. the maximum length of lobbies accessing uses not permitted on the ground floor level, shall be limited to a maximum street wall length, in total, of 25 percent of the street wall width of the building along the Tier C street frontage, or 25 linear feet of street wall along such street frontage, whichever is less. The minimum width of such lobbies need not be less than 10 feet.
   
   However, in C4 through C7 Districts where the floor area ratio for commercial uses is greater than or equal to 10.0, the maximum lobby length shall be modified such that the maximum street wall length, in total, shall not exceed 25 percent of the street wall width of the building along the Tier C street frontage, or 50 linear feet of street wall along such street frontage, whichever is less. The minimum width of such lobbies need not be less than 20 feet;
3. no parking spaces or loading berths shall be permitted within the minimum qualifying depth; and
4. in C4 through C7 Districts where the floor area ratio for commercial uses is greater than or equal to 10.0, for buildings with a street wall width greater than 50 feet, within the portion of the ground floor level street frontage that is required to be allocated to non-residential uses to the minimum qualifying depth, at least 50 percent of such frontage shall be allocated to uses in Use Groups VI or VIII.