The street wall of any building with frontage on Fifth Avenue shall extend without setback from the Fifth Avenue street line for at least 90 percent of the entire length of the front lot line. The street wall shall reach a minimum required height of 85 feet and shall not exceed a height of 125 feet at or within 10 feet of the street line.

Where a building occupies less than an entire block front of Fifth Avenue frontage, the height of the street wall at the street line shall be not more than 10 feet above or below the height of an adjacent existing building at the street line. If the building is on an interior lot between two adjacent existing buildings of different heights, the height of such building’s street wall at the street line shall be not more than 10 feet above or below the street wall height of one of the adjacent existing buildings at the street line. However, this shall not be construed to permit a street wall height of less than 85 feet or more than 125 feet at the street line. At the required height of the building’s street wall at the street line, the street wall must extend continuously without setback for at least 75 percent of its required width and no portion of its required width shall be set back more than 10 feet from the street line.

For the purpose of calculating the maximum street wall height on the narrow street frontage of a corner lot by the weighted average method, as set forth in paragraph (b) of Section 81-262 (Maximum height of front wall at the street line), the maximum street wall height generally applicable along the narrow street shall be averaged with a height of 150 feet for the first 100 feet from the street line intersection, provided that no actual street wall either on the Fifth Avenue or on the narrow street frontage shall exceed a height of 125 feet at the street line.

Below the minimum required street wall height, recesses whose depth shall be measured in all cases from the street line, shall be permitted only as follows: no recesses greater than 10 feet deep shall be permitted; recesses up to 10 feet deep shall be limited in their aggregate area to no more than 30 percent of the area of the street wall below the minimum required street wall height; in addition, recesses up to two feet deep shall be limited in their aggregate area to no more than 20 percent of the area of the street wall below the minimum required street wall height; and recesses up to one foot deep shall not be limited in their aggregate area. For the area above the minimum required street wall height, recesses are not restricted.

Above a height of 125 feet, a street wall shall be set back not less than 10 feet from the street line.