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Bethany Hubbard/MEDILL


Windy City soars sky-high

by Bethany Hubbard
April 12, 2011


Chicago is home to an array of architectural landmarks that are both innovative in design and engineering. Significant in the rise of the skyscraper, Chicago provided fertile ground for architects looking to make their marks.

The Great Chicago Fire, in 1871, destroyed more than 17,000 structures, according to pbs.org. The tragedy offered a unique opportunity for designers and architects to start from scratch. With new engineering techniques in mind, innovators such as Daniel Burnham, John Root, and Louis Sullivan began to build the Chicago we know today.

Early tall buildings relied on their outer walls for support. Subsequently, walls had to be extremely thick in order to hold the weight of the structure.

The north half of the Monadnock Building, at 53 W. Jackson Blvd., has six-foot thick brick walls at its base, according to the building’s website. The south half demonstrates the move to steel, and what would become known as a curtain wall.

The curtain wall frame on most modern buildings does not support the weight of the structure. This façade instead functions as a shield against the elements.

In some modern skyscrapers, steel frames surround bundled tubes that share the weight of the building.

“The Willis Tower is basically a bundle of nine square tubes,” said Sean Keller, associate professor of architecture at Illinois Institute of Technology. “It’s as if you took nine pieces of spaghetti and held them together. It makes it actually quite rigid and quite strong as a structure.”

This design enabled Willis, known as the Sears Tower until mid-2009, to reach 110 stories. The building was the tallest in the world until 1998 when it lost the record to the Petronas Towers in Malaysia.

The idea of a building reaching such heights would have been unfathomable to early architects.

“There are always the engineering issues, and those are interesting, but there are also the aesthetic issues,” Keller said. “How can you handle a tall building in a way that was pleasing, because it wasn’t like anything in the history of architecture? There were no tall buildings in ancient Rome, no office buildings.”

He said that architects still grapple with design that is both structurally sound, and visually appealing.

With height comes greater risk. Gusts of wind that would have grazed right over earlier designs, pose a real threat to those that soar into the clouds.

“If you have a building that’s rigid, for example, and really tall, and you have no flexibility, you’re going to have structural damage,“ said Phyllis Kozlowski, director of education for Wendella Boat Tours, which offers architectural tours on the Chicago River.

Kozlowski said that Willis, which actually moves slightly in the wind, was designed with this in mind.

The Chicago Spire, with a proposed 150 floors, would have been the tallest building in North America. But, when the economy tanked, so did plans for this next great Chicago icon.

As the country struggles to crawl out of an economic ditch, new buildings are no longer a certainty. Keller said that how tall buildings fit into a sustainable environment could also become important in the future.

“I think if they’re designed properly, they can sustain themselves, essentially through using wind,” he said. “If you handle heat and lighting correctly they can almost heat and cool themselves.”

But, Keller said this isn’t the case with most tall buildings today.

Gregory Dreicer, vice president of interpretation and exhibitions for the Chicago Architecture Foundation, said that while skyscrapers may embody power and money, they also unite Windy City dwellers.

“There’s a lot of local pride, and I think that’s good. It’s a strength of Chicago. It’s the reason people like to be here and want to come here.”