Skyscraper design must contend with the problem once described by architectural historian Francis Morrone as “oppressive fenestration.” No one’s going to rent space in a building without natural light, but nor is there anything admirable about an exterior that’s just one window after another. Setbacks break up facades and give them character.

New York architects were also up against the enormous aesthetic nuisance that is the city’s grid system. Laid out by state government in the early 19th century, the grid maximized opportunities for real estate development by establishing a uniform, tightly-knit pattern of streets and avenues throughout most of Manhattan. But buildings, like paintings, need a frame to be seen to advantage. Skyscrapers rising up from the grid can only be appreciated by craning one’s neck at an impossible angle or as a feature of the skyline, which is to say they cannot truly be appreciated at all. Exceptions that prove the rule include the Flatiron building, which sits on an irregular wedge formed by the intersection of Broadway and Fifth Avenue and 30 Rockefeller Center when admired from across the Channel Gardens. But such vistas are rare in the city. Setbacks lighten massings as one traces buildings’ ascent, thus providing a kind of vertical compensation for the New York landscape’s lack of appropriate horizontal context.

The intersection of government regulation, economic factors and architects’ ingenuity produced great variety within the overall Art Deco skyscraper aesthetic. One result was fortress-like piles, such as the Metropolitan Life North building on Madison Square and Ralph Walker’s Barclay-Vesey building. Some setback skyscrapers are classically-proportioned and very serious (Empire State Building) others are asymmetrical (500 Fifth Ave., by the same architect) and give full reign to the exuberance often associated with Art Deco design (Chrysler Building).

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Setback style was one of the important cultural exports of Jazz Age New York. In her book Form Follows Finance, Carol Willis notes that architects working in cities such Detroit, St. Louis, Pittsburgh and San Francisco where zoning law did not require setbacks nonetheless made use of them for aesthetic reasons.