For all buildings, 100 percent of the width of street walls along a street frontage at the ground floor level shall be located within eight feet of the street line. For any story above the ground floor level, at least 70 percent of the width of street walls shall be located within eight feet of the street line and extend to at least a minimum base height of 60 feet, or the height of the building, whichever is less; or as modified by Section 121-332 (Base Height Regulations). Up to 30 percent of the aggregate width of street walls above the ground floor may be recessed beyond eight feet of the street line, provided that any such recesses deeper than 10 feet along a wide street or 15 feet along a narrow street are located within an outer court. In addition, the street wall location provision of this paragraph shall not apply along such street line occupied by a public plaza as set forth in Section 37-70 (PUBLIC PLAZAS), nor within 15 feet of a landmark building or other structure.