For buildings, or portions thereof, with ground floor use and depth requirements, uses on the first story of a building, and within 15 feet of the ground floor level street wall, shall be limited to community facility uses, except for lobbies, entrances and exits to accessory parking facilities, and entryways to subway stations, as applicable, provided in accordance with Section 26-53 (Maximum Width of Certain Uses).  However, such minimum depth requirement may be reduced, to the minimum extent necessary, to accommodate vertical circulation cores or structural columns associated with upper stories of the building.