Citicorp Center
THE 59-STORY, 915-foot-tall Citicorp Center, containing 1.3 million square feet, is sheathed in space-age aluminum and mirrored glass, and floats on 114-foot tall supercolumns. This is the city’s first postmodern skyscraper, and it changed the playing fie
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h e 5 9 - s t o r y , 915-foot-tall Citicorp Center, containing 1.3 million square feet, is sheathed in space-age aluminum and mirrored glass, and floats on 114-foot tall supercolumns. This is the city’s first postmodern skyscraper, and it changed the playing field forever. The Boston-based architect Hugh Stubbins violated two axioms of the Internationalist aesthetic in the construction of this building. The first was the absolute ban on applied symbolic decoration. The Citicorp’s distinctive triangular top was the first purely decorative crown on a skyscraper since the Art Deco era. The crown had an ostensible function—it was intended to be a solar panel in the energyconscious 1970s, but it was never used as such, and ultimately became simply a design expression. There was a ripple effect in the architecture world, like the discovery of the emperor’s new clothes: flat tops were not an absolute verity after all, but simply another style among many to chose from. Citicorp laid the groundwork for
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the fanciful variations of the 1980s and 1990s, such as Philip Johnson’s Chippendale top for the AT&T Building, Helmut Jahn’s ball-topped 750 Lexington Avenue (1987), and the faceted Louis Vuitton headquarters (1999) by Christian de Portzamparc on East 57th Street. Citicorp is also a departure from the rule of strict structural expression. Just what holds this building up, anyway? The flush glass curtain wall with aluminum spandrels does not offer any clues. There is a bit of engineering legerdemain going on here: four supercolumns, flush with the sides but moved in and centered at 72 feet from the cantilevered corners, support the building along with the octagonal elevator core, which stands exposed in the center. Additional support is provided by the discreet bustle of the shopping mall in the rear, which functions like an anchorage on a suspension bridge to counteract the weight of the cantilevered structure. The skyscraper was one of the first buildings in the world to use a tuned mass damper, a 400-ton, 30-foot-square, 8-½-foot-thick block
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HUGH STUBBINS ,
1978
of concrete in the crown that slides on a thin layer of oil to convey its inertia to the building’s structure under high-wind stress. The mass is “tuned” to counteract the oscillation of the swaying building, and reduces the motion by almost half. Diagonal windbraces, repeated on an eight-story module, run along the perimeter and are concealed by the skin. After Citicorp was built, an engineer discovered a fatal design flaw: the bolted joints were vulnerable to stress in the extremely high winds that occur once every 16 or so years in New York. Welders worked around the clock to add bolted, steelreinforced plates over the joints. The quality of public space here is quite good. Not since Rockefeller Center have such pleasant plazas and interior spaces been accessible from the subway. The steps leading from street level down to the main entrance double as seating, and Citicorp’s open base makes the space seem more like a
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