Today marks the centennial of the passing of New York City's 1916 Zoning Law. At the time height limits were common in other cities such as Chicago which set a 130-foot limit. Between 1911 and 1913 New Yorkers became concerned with overbuilding and the rate of vacant office space. As the guidelines for how to curb this overbuilding were being proposed the 542-foot tall, full block wide Equitable Building at 120 Broadway was built, symbolizing the potential of unregulated development in the city. The 1916 zoning resolution separated districts by use (including business, residential and unrestricted) and limited the bulk of buildings. The zoning envelope had the greatest impact on the built environment of the city. The idea of stepping back upper floors to allow more light, combined with Ernest Flagg's plan for allowing a tower on 25% of the site shaped this new formula, as explained by The Skyscraper Museum: "The concept of the zoning envelope was the most innovative aspect of the 1916 ordinance... There were five formulas regulating the height and bulk of buildings. All were based on the width of the street and on the setback principle, but each resulted in a slightly different spatial envelope. For example, in a "1 ½-times district," if the street were 100 feet wide, the facade could rise sheer to 150 feet before the first setback. Above that level, the mass had to step back in a ratio of 1:3, that is, a one-foot setback for each three feet of additional height. In a "two-times district," if the width of the street were 100 feet, the building could reach 200 feet before it had to begin stepping back at the rate of one foot for each four feet of additional height. Most of Manhattan was liberally zoned as 1, 1 ½, 2, 2 ½ -times districts... The different formulas produced many permutations because both the width of streets and avenues and the factor of multiplication varied. In general, buildings on avenues could rise sheer for about 14 to 18 floors. On side streets, they were generally 9 to 12 stories before the first setback." #zoning #1916zoningresolution #setback #skyscraper #architecture #cityplanning (at Equitable Building - 120 Broadway)
