Essential Architecture-  Chicago Loop South

Sears Tower


Skidmore, Owings & Merrill (SOM)


233 South Wacker Drive, Chicago, Illinois 60606.






steel frame, curtain wall. Sears Tower was the world's tallest building from 1973 to 1998.


Office Building
  angle view upward, photo, M. Brack.
  view upward, photo, J. Cohen and general view from below, photo 1976, D. Stillman.
  overall view, photo 1978, R. Longstreth.
The Sears Tower is a skyscraper in Chicago, Illinois. It has been the tallest building in the United States since 1973, surpassing the World Trade Center, which itself had surpassed the Empire State Building only a year earlier. Commissioned by Sears, Roebuck and Company, it was designed by chief architect Bruce Graham and structural engineer Fazlur Khan of Skidmore, Owings and Merrill.

Construction commenced in August 1970 and the building reached its originally anticipated maximum height on May 3, 1973. When completed, the Sears Tower had overtaken the roof of the World Trade Center in New York City as the world's tallest building. The tower has 108 stories as counted by standard methods, though the building owners count the main roof as 109 and the mechanical penthouse roof as 110. The distance to the roof is 1,451 feet (442 m), measured from the east entrance.[3]

In February 1982, two television antennas were added to the structure, increasing its total height to 1,705 feet (520 m). The western antenna was later extended to 1,730 feet (527 m)[4] on June 5, 2000 to improve reception of local NBC station WMAQ-TV.

Black bands appear on the tower around the 29th–32nd, 64th–65th, 88th–89th, and 104th–109th floors. These are louvers which allow ventilation for service equipment and obscure the structure's belt trusses which Sears Roebuck did not want to be visible as on the John Hancock Center.

The building's official address is 233 South Wacker Drive, Chicago, Illinois 60606.

On August 12, 2007, the Burj Dubai in Dubai, United Arab Emirates was reported by its developers to have surpassed the Sears Tower in all height categories.[5] It overtook the Sears Tower antenna (1,730 feet, 527.3 m) and the building now currently stands at least 192 feet (58.4 m) taller (1,921.6 feet, 585.7 m).


Planning and construction
In 1969, Sears, Roebuck & Co. was the largest retailer in the world, with about 350,000 employees.[citation needed] Sears executives decided to consolidate the thousands of employees in offices distributed throughout the Chicago area into one building on the western edge of Chicago's Loop. With immediate space demands of 3 million square feet (279,000 m²), and with predictions and plans for future growth necessitating even more space than that, architects for Skidmore knew that the building would be one of the largest office buildings in the world.[citation needed]

Sears executives decided early on that the space they would immediately occupy should be efficiently designed to house the small army that was their Merchandise Group. However, floor space for future growth would be rented out to smaller firms and businesses until Sears could retake it. Therefore, the floor sizes would need to be smaller, and to have a higher window-space to floor-space ratio, to be more attractive and marketable to these prospective lessees. Smaller floor sizes necessitated a taller structure. Skidmore architects proposed a tower which would have large 55,000-square-foot (5,000 m²) floors in the lower part of the building, and would gradually taper the area of the floors down in a series of setbacks, which would give the Sears Tower its distinctive, husky-shouldered look.

As Sears continued to offer optimistic projections for future growth, the tower's proposed height soared into the low hundreds of floors and surpassed the height of New York's unfinished World Trade Center to become the world's tallest building. Restricted in height not by physical limitation or imagination but rather by a limit imposed by the Federal Aviation Administration to protect air traffic, the Sears Tower would be financed completely out of Sears' deep pockets, and topped with two antennae to permit local television and radio broadcasts. Sears and the City of Chicago approved the design, and the first steel was put in place in April 1971. The structure was completed in May 1973. Construction costs totaled approximately $150 million USD at the time,[6] which would be equivalent to roughly $950 million USD in 2005. For comparison, Taipei's Taipei 101, built in 2004, cost around the equivalent of US$1.64 billion in 2005 dollars.

However, Sears' optimistic growth projections never came to pass. Competition from its traditional rivals (like Montgomery Ward) continued, only to be surpassed in strength by other retailing giants like Kmart, Kohl's, and Wal-Mart. The fortunes of Sears & Roebuck declined in the 1970s as the company lost market share and its management grew ever more cautious.[7] The Sears Tower itself was not the draw Sears hoped it would be. The tower stood half-vacant for a decade as more office space was erected in Chicago in the 1980s. The company was eventually obliged to take out a mortgage on its signature building. Sears began moving its offices out of the Sears Tower in 1993 and had completely vacated the building by 1995, moving to a new office campus in Hoffman Estates, Illinois.

Sears Tower has gone through several owners in the years since but Sears has retained the naming rights for the building. It is now a multi-tenant office building with more than 100 different companies in residence, including major law firms, insurance companies and financial services firms.

The Skydeck
The Sears Tower Skydeck observation deck opened on June 22, 1974 and is located on the 103rd floor of the tower. It is 1,353 feet (412 m) above ground and is one of the most famous tourist attractions in Chicago. Tourists can experience how the building sways on a windy day. They can see far over the plains of Illinois and across Lake Michigan to Indiana, Michigan and Wisconsin on a clear day. It takes about 45 seconds to soar to the top in either of two special elevators. The Sears Tower Skydeck competes with the John Hancock Center's observation floor a mile and a half away, which is 323 feet (98 m) lower.

A second Skydeck on the 99th floor is used when the 103rd floor is closed.

The tourist entrance can be found on the south side of the building along Jackson Boulevard.

Without warning, in August 1999 French urban climber Alain "Spiderman" Robert, using only his bare hands and feet scaled the building's exterior glass and steel wall all the way to the top. A thick fog settled in near the end of his climb, making the last 20 floors of the building's glass and steel slippery.[8]
Sears Tower as seen from John Hancock Center observation deck
900 North Michigan, Park Tower, the John Hancock Center, and Water Tower Place (L-R) as seen from the Sears Tower observation deck

Which is the tallest?

Height comparison with other tall buildings.At 1,483 feet (452 m) tall, including decorative spires, the Petronas Twin Towers in Kuala Lumpur, Malaysia, laid claim to replacing the Sears Tower as the tallest building in the world in 1998. Not everyone agreed, and in the ensuing controversy four different categories of "tallest building" were created. Of these, Petronas was the tallest in one category (height to top of architectural elements, meaning spires but not antennas). However, before the addition of the Sears Tower's own two antennas in 1982, One World Trade Center was taller by height to top of its 360-foot (110 m) antenna (added in 1978 to its previous 1368-foot (417 m) height).

Taipei 101 in Taiwan claimed the record in three of the four categories in 2004 to become generally recognized as the tallest building in the world. Taipei 101 surpassed the Petronas Twin Towers in spire height and the Sears Tower in roof height; it also claimed the record for highest occupied floor. The Sears Tower retained one record: its antenna exceeded the Taipei 101's spire in height.

The Sears Tower remained the tallest office building in North America, and retains the world record when measuring from sidewalk level of the main entrance to the top of the antenna. When completed, the Freedom Tower in New York City is expected to surpass the Sears Tower through its structural but not occupied peak. Burj Dubai, currently under construction in Dubai, is expected to claim world records in a number of categories, surpassing the Sears Tower, Taipei 101 and the CN Tower, when it opens in 2009. The Chicago Spire now under construction is expected to lay claim to most height records for North American structures the following year.

Cultural depictions

Film and television
The Sears Tower appears in numerous films and television shows set in Chicago such as Ferris Bueller's Day Off, Ferris and company watch the streets of Chicago from the observation deck.[9] The television show Late Night with Conan O'Brien introduced a character called The Sears Tower Dressed In Sears Clothing when the show visited Chicago in 2006.[10] In a commercial for McDonald's featuring Michael Jordan and Larry Bird, the two basketball legends negotiate a basket off the top of the Sears Tower.[11] In an episode of the television series, Monk, Adrian Monk tries to conquer his fear of heights by imagining that he is on top of the Sears Tower. The tower is seen in the PC game Command and Conquer: Red Alert 2[12] and the Rampage series of video games. The tower is also featured in SimCity PC games.

In 2007, the construction of the Sears Tower was parodied in the literary journal McSweeney's, in a piece of flash fiction entitled In the Early '70s, A Chicago Native Approves of the Sears Tower Construction, In Anticipation of It Beating The World Trade Center for Tallest Building in the World.[13] A scene in Andrew M. Greeley's 2005 novel, The Bishop in the Old Neighborhood: A Blackie Ryan Story, occurs in downtown Chicago, overlooking the Sears Tower. The Sears Tower is mentioned briefly in the novel Everything Is Illuminated by Jonathan Safran Foer.

Position in Chicago's skyline

Figures and statistics

Sears Tower viewed from S Wacker Dr.The top of the Sears Tower is the highest point in Illinois. The tip of its highest antenna is 1,730 feet (527.3 m) or 2,325 feet (708 m) above sea level, its roof is 1,451 feet (442.3 m) above street level or 2,046 feet (623 m) above sea level, the 103rd floor observation deck (The Sky deck) is 412 m (1,353 ft) above street level or 1,948 feet (593 m) above sea level, the Wacker Drive main entrance is 595 feet (181 m) above sea level. (The highest natural point in Illinois is the Charles Mound, at 1,235 feet (376 m) above sea level.)
The building leans about 4 inches (10 cm) from vertical due to its slightly asymmetrical design, placing unequal loads on its foundation. This can occasionally be felt.
The antennae of the Sears Tower are struck by lightning an average of 650-675 times per year.[citation needed]
The design for the Sears Tower incorporates nine steel-unit square tubes in a 3 tube by 3 tube arrangement, with each tube having the footprint of 75 x 75 feet (22 x 22 m). The Sears Tower was the first building for which this design was used. The design allows future growth of extra height to the tower if wanted or needed. [14]
The restrooms on the 103rd floor sky deck 1,353 feet (412 m) above street level are the highest in the world.

^ SkyscraperPage - Sears Tower, source: Federal Communications Commission, CTBUH
^ Databank: Sears Tower Retrieved on November 19th, 2007
^ For information on this transformation, see Donald R. Katz The Big Store: Inside the Crisis and Revolution at Sears, New York (Viking), 1987.
^ The Sears Tower Dressed In Sears Clothing

Society of Architectural Historians

Special thanks to the Society of Architectural Historians
for some of the images on this page (copyright SAH).