C1 C2 C4 C5 C6

In the districts indicated without a letter suffix, when a mixed building is subject to tower regulations, the residential tower regulations of paragraphs (a) and (b) or the commercial tower regulations of paragraph (c) of this Section shall apply to the entire building.

(a)        In C1 or C2 Districts mapped within R9 or R10 Districts, or in C1-8, C1-9, C2-7 or C2-8 Districts, a mixed building that meets the location and floor area criteria of paragraph (a) of Section 23-65 (Tower Regulations) shall be governed by the provisions of Section 23-651 (Tower-on-a-base), except that the building base regulations of paragraph (b) of Section 23-651 shall be modified, as follows:

(1)        On a wide street, and on a narrow street within 30 feet of its intersection with a wide street, the entire width of the street wall of a base shall be located on the street line.

However, to allow for articulation of corners at the intersection of two street lines, the street wall may be located anywhere within an area bounded by the two street lines and a line connecting such street lines at points 15 feet from their intersection. Recesses, not to exceed three feet in depth from the street line, shall be permitted on the ground floor where required to provide access to the building.

(2)        On a narrow street beyond 30 feet of its intersection with a wide street, the street wall of a base shall be located within eight feet of a street line.

(3)        On a wide street, recesses above the ground floor are permitted at any level in the street wall of a base for outer courts or balconies. The aggregate width of such recesses shall not exceed 50 percent of the width of the entire street wall at any level.

However, not more than 30 percent of the aggregate width of such recesses shall exceed a depth of eight feet. Furthermore, no recesses shall be permitted below a height of 12 feet, within 20 feet of an adjacent building, or within 30 feet of the intersection of two street lines, except for corner articulation as provided for in paragraph (a)(1) of this Section.

(4)        On a narrow street, recesses are permitted at any level in the street wall of a base for outer courts or balconies. The aggregate width of such recesses shall not exceed 50 percent of the width of the entire street wall at any level.

However, not more than 30 percent of the aggregate width of such recesses shall exceed a depth of eight feet. Furthermore, no recesses shall be permitted below a height of 12 feet within 20 feet of an adjacent building, or within 30 feet of the intersection of two street lines, except for corner articulation as provided for in paragraph (a)(1) of this Section.

(b)        In C4-6, C5-1 or C6-3 Districts, the residential portion of a mixed building that in the aggregate occupies not more than 40 percent of the lot area of a zoning lot or, for zoning lots of less than 20,000 square feet, the percent set forth in Section 23-65, may be constructed in conformance with the provisions of Section 23-652 (Standard tower), provided the following conditions are met:

(1)        at least 65 percent of the total allowable floor area on a zoning lot under the applicable district regulations is occupied by residential uses;

(2)        all uses within such mixed building comply with the provisions of Section 32-42 (Location Within Buildings); and

(3)        only the residential portion of such mixed building penetrates the sky exposure plane as set forth in Sections 33-432 or 33-442 (In other Commercial Districts).

(c)        In C4-7, C5-2, C5-3, C5-4, C5-5, C6-4, C6-5, C6-6, C6-7, C6-8 or C6-9 Districts, the tower regulations applicable to any mixed building shall be the regulations set forth in Section 33-45.

However, in C4-7, C5-2, C5-4, C6-4, C6-5 or C6-8 Districts, when no more than two stories of a mixed building are occupied by non-residential uses, the tower regulations applicable to the residential portion of such mixed building may be governed by Section 23-652 or, for towers on small lots, the percentages set forth in Section 23-65.

All uses within such mixed building shall comply with the provisions of Section 32-42.