Aon Center (200 East Randolph Street, formerly
Amoco Building) is a modern skyscraper in Chicago, Illinois, United States, designed by architect firms Edward Durell Stone and The Perkins and
Will partnership, and completed in 1973 as the Standard Oil
Building. With 83 floors and a height of
1,136 feet (346 m), it is the third tallest building in
Chicago, surpassed in height by the Willis Tower and the Trump International Hotel and
The building is managed by Jones Lang LaSalle
The Aon Center.
The Standard Oil Building was constructed as the new headquarters
of the Standard Oil Company of Indiana
had previously been housed at South Michigan Avenue and East 9th
Street. When it was completed in 1973 it was the tallest building
in Chicago and the fourth-tallest in the world, earning it the
nickname "Big Stan". (A year later, the Sears Tower took the title as Chicago's and world's tallest.)
The building employs a tubular steel-framed structural system with
V-shaped perimeter columns to resist earthquakes, reduce sway, minimize column
bending, and maximize column-free space. This construction
method was also used for the World Trade Center towers in New York City.
completed, it was the world's tallest marble-clad building, being sheathed entirely with
43,000 slabs of Italian Carrara marble.
The marble used was thinner than previously
attempted in cladding a building; this quickly proved to be a
mistake. In 1974, just a year after completion, one of the marble
slabs detached from the façade and penetrated the roof of the
nearby Prudential Center Annex. Further inspection found numerous
cracks & bowing in the marble cladding of the building. To
alleviate the problem, stainless steel straps were added to hold
the marble in place. Later, from 1990 to 1992, the entire building
was refaced with Mount Airy white granite at an
estimated cost of over $80 million. (Amoco was reticent to
divulge the actual amount, but it was well over half the original
price of the building, without adjustment for inflation.) The
discarded marble was crushed and used as landscaping decoration at
Amoco's refinery in Whiting, Indiana. The building's facade now somewhat resembles
that of the World Trade
Center due to the upward flow of the columns.
The Standard Oil Building was renamed the Amoco Building when the
company changed names in 1985. In 1998, Amoco sold the building to
The Blackstone Group
undisclosed amount, estimated to be between $430 and $440 million.
It was renamed as the Aon Center on December 30, 1999, although the
would not become the
building's primary tenant until September 2001. In May 2003, Wells
Real Estate Investment Trust, Inc. acquired the building for
between $465 and $475 million.(On August 10, 2007, Wells Real
Estate Investment Trust, Inc. changed its name to Piedmont Office
Realty Trust, Inc.)
In the early 1980s, the lights in selected offices in the building
were turned on to form a huge cross during the Christmas
season. In recent years, the top floors
of the building have been lit at night with colors to reflect a
particular season or holiday. Orange is used for Thanksgiving
, green or red for Christmas, and
pink during Breast Cancer
lighting commonly matches the nighttime lighting on the antenna of Willis Tower, the John Hancock
Center and the upper floors of the Merchandise Mart.
In the plaza, there is a Sounding Sculpture by Harry Bertoia
Position in Chicago's skyline
- " Contact Us." AON Corporation. Retrieved on January
- " Chicago." SkyTeam. Retrieved on January 31, 2009.
- " Strata Decision Technology Chicago Office Relocates."
Retrieved on February 24, 2009.