We’ve talked about Sears Tower and Trump Tower which are the two highest buildings in Chicago. Now is time to talk about Aon Center, the third highest building in the city.
Designed in 1974 by architect firms Edward Durell Stone and The Perkins and Will partnership it has 83 floors and a height of 1,136 feet (346 m). At the time of its completion, this was the fourth-tallest building in the world and the world’s tallest marble-clad building (being sheathed entirely with 43,000 slabs of Carrara marble). The disposition of the slabs compose a series of vertical stripes that add extra visual height to its already impressive stature.
However, this wasn’t the most appropriate system since little after the building was completed its facade began to buckle. Stainless steel straps were wrapped around the building to keep any large chunks from falling off. It was all replaced with white granite at a very very very high cost (half what it cost to build the tower).
The building’s stone facade provides such contrast against the other buildings that as Chicago skyline grows, it becomes more prevalent, providing three dimensional form.
Aon Center has a sunken plaza in front of the building with extensive fountain work. This creates an area that is a pleasure for people on hot summer days, while at the same time protects the building from would-be truck bombers.
Its structure is based on a tubular steel-framed structural system with V-shaped perimeter columns that not only reduce sway but also minimize column bending and maximize column-free space. Therefore it resists earthquakes. This construction method was also used for the World Trade Center Towers (NY).
And you are wondering, what do people see from this building? Height and location give the Aon Center’s users remarkable views in all directions. People facing south look over Grant Park; people with west-facing windows can look at The Loop; people with eastern exposures are treated to Lake Michigan sunrises and boating activities; and people on the northern face get to look up the Magnificent Mile and the Chicago coastline.
If you happen to see the building at night, you could observe that the top floors are lit with specific colours depending on the season: Orange-Thanksgiving, green/red-Christmas, and pink-National Breast Cancer Awareness Month. The lighting commonly matches the nighttime lighting on the antenna of Willis Tower, the John Hancock Center and the upper floors of the Merchandise Mart.
Enjoy your Aon Center visit and feel free to share your experience with the Skyliners! Safe travels!!