Architectural Record BE - Building Enclosure

Revival of an Icon

The United Nations renovation team brings back the long-faded luster of the Secretariat while satisfying ambitious performance goals.
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From Architectural Record
Joann Gonchar, AIA
Continuing Education

Learning Objectives - After this course, you should be able to:

  1. Outline the early history of curtain-wall cladding on tall buildings and explain the technological and historical significance of the Secretariat’s curtain wall.
  2. Describe the performance problems of the Secretariat’s curtain wall and explain the causes of those problems.
  3. Explain the renovation team’s strategy for addressing those problems.
  4. Explain the renovation team’s strategy for complying with new codes and satisfying goals for energy conservation, security, and occupant comfort.



Early in July, the first of more than 3,000 United Nations officials began to move back into the newly renovated Secretariat, the 39-story office tower that is the most visible element of the organization's 17-acre campus on the eastern edge of Midtown Manhattan. The high-rise is the first piece of a multiphase capital plan for the revamping of the U.N. slated for completion in 2014 and now projected to cost about $2.3 billion, according to the U.S. Government Accountability Office.

The rational and prismatic Secretariat, with its billboard-thin profile and once-again-glittering skin, is the embodiment of post–World War II optimism. It represents the ideals of the age more succinctly than the sculptural General Assembly or the low, rectangular conference building—the other components in the early-1950s trio of U.N. buildings designed by an international team that included Le Corbusier, Oscar Niemeyer, and Wallace Harrison.

In recent decades the Secretariat, along with the rest of the now six-building, 2.6 million-square-foot complex, had lost much of its luster and become increasingly outmoded: It was riddled with asbestos, had mechanical systems that were outdated and grossly inefficient, and lacked many of the most basic life-safety features, including sprinklers. Over the years, fixes intended to address numerous facade problems radically altered the appearance of the U.N. structures, especially the Secretariat. John Gering, managing partner at HLW, design architect for many aspects of the renovation project, likes to compare the gradual deterioration and recent transformation of the U.N. centerpiece to a Grimm's fairy tale. “The building was a prince that turned into a frog,” he says. “Our goal was to turn it back into a prince.”

The Secretariat is among a handful of mid-century U.S. buildings that realized the ideal of the crystalline tower. Pietro Belluschi's Equitable Building in Portland, Oregon, completed in 1947, was the first glass-and-aluminum-clad high-rise. Its concrete structure is closely wrapped with aluminum panels that are filled in with aluminum-framed glazing. The envelope strategy contrasts with that of the Secretariat, finished in 1950, whose primary elevations are enclosed by free-hanging glazed facades. And although another Manhattan building—Skidmore, Owings & Merrill's Lever House, completed two years later—was the first tower to be entirely enclosed by a curtain wall, the Secretariat holds the distinction of being the first tall building to employ such a suspended system, explains Robert Heintges. His eponymous firm is the architect of record for the envelopes of all the buildings included in the U.N.'s renovation plan.

The strikingly thin, 39-story Secretariat was the most prominent piece of the United Nations compound in the early 1950s (above), as it is today.

Photography: Ezra Stoller © Esto


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Originally published in Architectural Record