The tower provisions of this Section shall apply, as an option, to any zoning lot with a lot area of at least 10,000 square feet. Any portion of a building developed or enlarged on such zoning lots that exceeds the applicable maximum base height shall be constructed as either a point tower or a broad tower, as follows:

(a)        Point tower

(1)        Tower lot coverage and maximum length

Each story located entirely above a height of 75 feet shall not exceed a gross area of 6,800 square feet. The outermost walls of each story shall be inscribed within a rectangle, and the maximum length of any side of such rectangle shall be 85 feet.

(2)        Tower top articulation

The highest three stories, or as many stories as are located entirely above a height of 75 feet, whichever is less, shall have a lot coverage of at least 50 percent of the story immediately below such stories, and a maximum lot coverage of 80 percent of the story immediately below such stories. Such reduced lot coverage shall be achieved by one or more setbacks on each face of the tower, where at least one setback on each tower face has a depth of at least four feet, and a width that, individually or in the aggregate, is equal to at least 10 percent of the width of such respective tower face. For the purposes of this paragraph (a)(2), each tower shall have four tower faces, with each face being the side of a rectangle within which the outermost walls of the highest story not subject to the reduced lot coverage provisions have been inscribed. The required setbacks shall be measured from the outermost walls of the building facing each tower face. Required setback areas may overlap.

(b)        Broad tower

Each story located entirely above a height of 75 feet shall not exceed a gross area of 8,800 square feet. The outermost walls of each such story shall be inscribed within a rectangle, and the maximum length of any side of such rectangle shall be 135 feet. The upper stories shall provide setbacks with a minimum depth of 15 feet measured from the east facing wall of the story immediately below. Such setbacks shall be provided at the level of three different stories, or as many stories as are located entirely above a height of 75 feet, whichever is less. For towers with at least six stories located entirely above a height of 75 feet, the lowest level at which such setbacks may be provided is 100 feet, and the highest story shall be located entirely within the western half of the tower.

(c)        Orientation of all towers

The maximum length of the outermost walls of any side of each story of a building facing the shoreline that is entirely above a height of 75 feet shall not exceed 80 feet For the purposes of this Section, the street line of St. Marks Place shall be considered to be a line parallel to the shoreline, and any side of such rectangle facing St. Marks Place from which lines perpendicular to the street line of St Marks Place may be drawn, regardless of intervening structures, properties or streets, shall not exceed 80 feet.

(d)        Location of all towers

Any portion of a building that exceeds a height of 70 feet shall be no closer to a side lot line than eight feet, and any story of a building that is entirely above a height of 70 feet shall be located within 25 feet of a street line or sidewalk widening line, where applicable.

(e)        Maximum tower height

The maximum height of any building utilizing the tower provisions of this Section shall be 200 fet. The height of the tower portion of the building shall be measured from the base plane.

(f)        Tower and base integration

All portions of a building that exceed the applicable maximum base height set forth in Section 128-33 shall be set back at least 10 feet from the street wall of a building facing a wide street and at least 15 feet from the street wall of a building facing a narrow street. However, up to 50 percent of the street wall of the portion of the building located above a height of 75 feet need not be set back from the street wall of the building, and may rise without setback from grade, provided such portion of the building is set back at least 10 feet from a wide street line or sidewalk widening line, where applicable, and at least 15 feet from a narrow street line or sidewalk widening line, where applicable.

(g)        Tower exclusion areas

No building or other structure may exceed a height of 75 feet within the areas designated on Map 4 (Tower Restriction Areas) in the Appendix to this Chapter.