The following regulations shall apply to all buildings within Sites 1 through 6:

(a)        Street wall location

For the purposes of applying the height and setback regulations of this Section, inclusive, wherever a building fronts upon any publicly accessible open space, private street or pedestrian way, as shown on Map 3 (Subdistrict F: Public Access Area Plan) in Appendix B, the boundary of such publicly accessible open spaces, private streets or pedestrian ways shall be considered to be a street line. Furthermore, for the purposes of applying such height and setback regulations, the sidewalk widening line required along Eleventh Avenue shall be considered the Eleventh Avenue street line.

Wherever a building on Sites 1, 5 or 6 faces the High Line, the street wall shall not be located closer than five feet to the edge of the High Line, as shown on Map 3. Such five foot separation shall remain unobstructed, from the level of finished grade adjacent to a building, to the sky, except as permitted:

(1)        for that portion of a building on Site 5 located above a height of 50 feet as measured from the High Line bed, pursuant to Section 93-567 (Site 5);

(2)        for that portion of a building on Site 6 located below the High Line, pursuant to Section 93-568 (Site 6); and

(3)        pursuant to paragraph (d) of Section 93-756 (General requirements for the High Line).

(b)        Measurement of building heights

(1)        Measurement of building base and transition heights

For portions of a building that front upon a publicly accessible sidewalk, the maximum building base height and, where applicable, the maximum transition height of a street wall, shall be measured from the mean level of the public sidewalk that such street wall fronts upon. For portions of a building that front upon publicly accessible open spaces in which no sidewalks are provided adjacent to a street wall, the maximum building base height or, where applicable, the maximum transition height of a street wall, shall be measured from the mean level of the final grade of the open space that such street wall fronts upon. However, the following street wall heights shall be measured from the High Line bed:

(i)        on Site 6, the portion of a street wall above the High Line bed facing the High Line beyond 60 feet of Eleventh Avenue; and

(ii)        on Site 6, along the Southwest Open Space within 60 feet of the High Line.

(2)        Measurement of tower heights

The height of a tower shall be measured from the highest level of the public sidewalk or finished grade located nearest such tower, to the ceiling of the highest story of the tower where floor area occupies more than 75 percent of the gross area of such story. However, on Site 5, the height of the tower shall be measured from the High Line bed.

Where minimum height differences are required between towers, such heights, for each tower, shall be measured from the Manhattan Datum, which is 2.75 feet above sea level.

(c)        Towers

Criteria for towers on Sites 1 through 6 are set forth in this Section, inclusive. The minimum distance between all such towers shall be 60 feet.