(1) Legislative Findings. The Council finds that:

(a) The protection and enhancement of the high quality of the City's skyline is in the best interest of the City of Philadelphia.

(b) Historic views of the skyline and the City Hall Tower from Interstate 95, the Schuylkill Expressway, Broad street, the Belmont Plateau and the Benjamin Franklin Parkway contribute to the character of the City and must be retained for posterity.

(c) The City of Philadelphia has an economic interest in maintaining its skyline and views of the City Hall Tower in that these views have been traditionally identified with the City of Philadelphia and have been used to promote the City both as a tourist attraction and as an attractive location for business and industry.

(d) It is desirable to continue to promote the historic character of the City and the statue of William Penn has frequently been used as a symbol of the history of the City as well as a symbol of the history of the United States of America.

(e) At the time of its construction, the City Hall Tower was one of the tallest structures in the country. While it is not necessary for the tower to be the City's tallest structure, it is necessary to preserve its prominence on the skyline by the preservation of the traditional views of the tower.

(f) At present, only the existing Benjamin Franklin Parkway controls protect and enhance the City's skyline and traditional view corridors of the City Hall Tower.

(g) Therefore, additional special height controls are necessary to protect and enhance the City's skyline and to protect traditional view corridors of the City Hall Tower.

(h) The establishment of specific height maximums within the four zones shown on the accompanying Maps "A," "B" and "C" is necessary to accomplish the protection and enhancement of the City's skyline and traditional view corridors of the City Hall Tower.

(2) Scope.

(a) The special controls of this Section shall apply within the following zones, as defined:

(.1) Zone 1. The area which lies between the line bearing south fifty-four degrees forty-five minutes twenty-nine seconds east and the line bearing south fifty-three degrees nine minutes forty-five seconds east, and which is at least seven thousand one hundred sixty-five feet from that point on the Art Museum steps designated as N240740, E2719920 on the Pennsylvania State Plane Coordinate South Zone Map. Zone 1 generally is a corridor extending southeast from City Hall, and is illustrated in the accompanying Map "A."

(.2) Zone 2. The area which lies between the line bearing south fifty-three degrees nine minutes forty-five seconds east and the line bearing south forty-eight degrees forty-nine minutes fifty-nine seconds east, and which is at least seven thousand one hundred sixty-five feet from that point on the Art Museum steps designated as N240740, E2719920 on the Pennsylvania State Plane Coordinate South Zone Map. Zone 2 generally is a corridor extending southeast from City Hall, and is illustrated in the accompanying Map "A."

(.3) Zone 3. The area not more than two hundred sixty feet on either side of the line bearing north fifty-nine degrees fifty-one minutes twenty seconds east, beginning at City Hall Tower, and within the area bounded by the south side of Spring Garden street to the north and the west side of Fourth street to the east. Zone 3 generally is a corridor extending northeast of City Hall, and is illustrated in the accompanying Map "B."

(.4) Zone 4. The area marked "Zone 4" on the accompanying Map "C," being generally the area bounded by Arch street, Sixteenth street, Chestnut street, and Thirteenth street.

(b) All maps referenced in this Section shall be filed with the Department of Licenses and Inspections and the City Planning Commission, and shall be available for public inspection during normal business hours upon request.

(3) Maximum Heights. No building within any of the Zones listed in subsection (2) shall be erected or altered to be in excess of the following maximum heights (measured from 0 feet City Datum):

(a) Within Zone 1, the maximum height of a building at any point shall be determined by the formula (d x 0.05705) + 90 feet, where "d" is the distance in feet from any point of the building to the point on the Art Museum steps designated as N240740, E2719920 on the Pennsylvania State Plane Coordinates South Zone Map;

(b) Within Zone 2, the maximum height of a building at any point shall be determined by the formula (d x 0.02586) + 90 feet, where "d" is calculated as in subsection 3(a);

(c) Within Zone 3, the maximum height shall be determined as follows:

(.1) For any point of a building within one hundred feet on either side of the line bearing north fifty-nine degrees fifty-one minutes twenty seconds east as measured through the center line of City Hall Tower, the maximum height shall be three hundred thirty feet;

(.2) For any point of a building greater than one hundred feet from said line bearing north fifty-nine degrees fifty-one minutes twenty seconds east, but no more than two hundred sixty feet from said line, the maximum height shall increase above three hundred thirty feet along a forty-five degree recession plane, such that the maximum height at the outer edge of the recession plane (two hundred sixty feet from said line) shall be four hundred ninety feet;

(d) Within Zone 4, the maximum height shall be as designated on Map "C".

(4) Conflicting Height Limitations. If any part of a building is subject to more than one maximum height, whether established by this Section or established by or resulting from any other provision of this Title, the least maximum height shall control.