The regulations of Section 99-03 (Streetscape Regulations) may be modified for a community facility provided the City Planning Commission certifies that the treatment of the facade preserves and enhances street life on Madison Avenue compatible with the character of the surrounding area.

(a)        Street walls along Madison Avenue

For developments or enlarged portions of buildings with frontage on Madison Avenue or on a side street within 50 feet of its intersection with Madison Avenue, the following regulations shall apply:

(1)        The street wall of the base of such building shall be located on the street line or, if there is an existing abutting building fronting on the same street line that is set back from such street line, the street wall of the base may be aligned with the street wall of the abutting building for a distance of not less than 10 feet measured horizontally from the side wall of such abutting building. However, such setback distance shall not exceed 15 feet from the street line. All street walls built pursuant to this paragraph shall extend along the full length of the street line and rise vertically without setback for:

(i)        not less than 110 feet but not more than 120 feet above curb level ; or

(ii)        the full height of the building ;

whichever is less.

(2)        Above the base, a setback is required for all portions of a building which exceed a height of 120 feet above curb level. Such setback shall be provided at a height not lower than 110 feet above curb level, and shall have a minimum depth of 10 feet from a wide street line and a minimum depth of 15 feet from a narrow street line.

(3)        No portion of a building may exceed the height limitations of Section 99-054 (Maximum building height).

(b)        Street walls along side streets

For developments or enlarged portions of buildings with frontage on a side street beyond 50 feet of its intersection with Madison Avenue, the following regulations shall apply:

(1)        The street wall of the base of such building shall be located on the street line or, if there is an existing abutting building fronting on the same street line that is set back from such street line, the street wall of the base shall be aligned with the street wall of the abutting building for a distance of not less than 10 feet measured horizontally from the side wall of such abutting building. However, such setback distance need not exceed 10 feet from the street line. All street walls built pursuant to this paragraph shall extend along the full length of the street line and rise vertically without setback for:

(i)        a height of 60 feet above curb level ; or

(ii)        the height of a street wall before setback, if applicable, of that portion of an existing building nearest the development or enlargement, fronting on the same street line, and located on the same or an adjoining zoning lot ;

whichever is higher.

(2)        Alternatively, the street wall location provisions of paragraph (a) of this Section may apply to the base of a building along a side street beyond 50 feet of its intersection with Madison Avenue, up to a distance of 70 feet from its intersection with Madison Avenue.

(3)        Above the base, a setback is required for all portions of a building. Such setback shall have a minimum depth of 10 feet from a wide street line and a minimum depth of 15 feet from a narrow street line.

(4)        No portion of a building may exceed the height limitations of Section 99-054 (Maximum building height).

(c)        Street walls in Historic Districts

For any zoning lot located in a Historic District designated by the Landmarks Preservation Commission, the minimum base height and street wall location regulations of this Section shall be modified as follows:

(1)        The minimum base height of a street wall may vary between the height of the street wall of an adjacent building before setback, if such height is lower than the minimum base height required, up to the minimum base height requirements of this Section.

(2)        The location of the street wall of any building may vary between the street wall location requirements of this Section, and the location of the street wall of an adjacent building fronting on the same street line.

(a)        Recesses

Recesses are permitted to provide outer courts, balconies or articulation of street walls at the intersection of two street lines. In addition, recesses may be required or prohibited due to the width of the zoning lot or the location of the street wall of an adjacent building. For the purposes of this Section, the provisions of Section 23-842 (Wide outer courts) shall not apply. In lieu thereof, the width of any such court shall be at least one and one-third times its depth. All recesses shall be provided in accordance with the following provisions:

(1)        Above a height of 20 feet above curb level, or above the level of the second story, whichever is lower, up to 30 percent of the street wall of a base may be recessed from the street line. However, no recesses shall be permitted within 30 feet of the intersection of two street lines, unless such recesses are provided within an area bounded by the two street lines and a line connecting such street lines at points 15 feet from their intersection.

(2)        Where the development or enlarged portion of a building is adjacent to an existing building located on a zoning lot having frontage on the same street line, no recesses shall be provided in the street wall of the development or enlargement for a distance of 10 feet from the adjacent corner of the existing building to a height equal to the height of the existing building.

(3)        Except for a zoning lot with less than 50 feet of frontage, or a zoning lot with less than 100 feet of frontage and located entirely in a Historic District designated by the Landmarks Preservation Commission, recesses are required on the street walls of buildings facing Madison Avenue, in accordance with the following provisions:

(i)        above a height of 20 feet above curb level, or above the level of the second story, whichever is lower, at least 25 percent of the length of the street wall of a base at the level of every story shall be recessed from the street line to a depth of at least five feet. Such recesses shall be unobstructed from their lowest level to the sky; and

(ii)        above the base, the street wall shall be articulated with recesses that occupy at least 20 percent of the length of the street wall at the level of every story to a depth of at least five feet. Such recesses shall be unobstructed from their lowest level to the sky.

(b)        Balconies

Balconies shall comply with the following provisions:

(1)        No balconies shall be permitted to extend beyond the street wall of the base built in accordance with the height and setback regulations of Section 99-051 (Location, height and setback of street wall), paragraph (a).

(2)        Balconies shall be permitted in recesses that are not required to be unobstructed from their lowest level to the sky.

(c)        Dormers

For the purposes of this Section, a dormer shall be a vertical extension of the street wall of a base allowed as a permitted obstruction within a required setback area. A dormer may be located anywhere on a wide street, and on a narrow street within 70 feet of its intersection with a wide street. However, a dormer shall not be located within 10 feet of a side lot line unless it fully abuts an adjoining building.

On any street frontage, the aggregate width of all dormers at the required setback level shall not exceed 60 percent of the width of the street wall of the highest story of the base. For each foot of height above the base, the aggregate width of all dormers at that height shall be decreased by one percent of the street wall width of the highest story of the base.

If the width of a street wall, built pursuant to Section 99-051 or 99-052, is 45 feet or less, then the building shall comply with the provisions of Section 23-692 (Height limitations for narrow buildings or enlargements).

The height of all buildings or other structures shall comply with the following provisions:

(a)        Except as otherwise provided in paragraph (b) of this Section, the height of all buildings or other structures shall not exceed 170 feet above curb level. However, such buildings or other structures may exceed 170 feet, to a height of 19 stories or 210 feet, whichever is less, provided that the gross area of each story located above 170 feet does not exceed 80 percent of the gross area of the story directly below it.

(b)        For the purposes of this Section, the Midblock Transition Portion shall be that portion of a zoning lot located within the area between 70 feet and 100 feet from the Madison Avenue street line, except for a zoning lot which has frontage on a wide street not located in a historic district. Within the Midblock Transition Portion, a building or other structure shall not penetrate an imaginary plane that begins above a line 100 feet from the Madison Avenue street line at a height of 20 feet above the height of a street wall built pursuant to Section 99-051, paragraph (b), and rises over the Midblock Transition Portion to a height of 120 feet above curb level at a distance of 70 feet from the Madison Avenue street line.