The Willis Tower

Formerly: The Sears Tower
Formerly: The Sears Building
Built: 1970-1974
Cost: $186,000,000
Designed by: Skidmore, Owings & Merrill
Renovated: 1985 by Skidmore, Owings and Merrill at a cost of $25,000,000
Renovated: 1994 by DeStefano and Partners
Type: Skyscraper
Stories: 110
Maximum Height: 1,729 feet / 527 meters
Maximum width: 195 feet
Maximum length: 195 feet
Location: 233 South Wacker Drive, Chicago, United States



Finest tower in the city known for its architecture is great, I have served Willis Tower for decades a symbol of the great engineering prowess and the triumph of architectural engineering.


Only a few years later a pioneer in building a tube attached that allows for 100 story John Hancock Center installed a few dozen blocks away, came the architects and engineers with the same revolutionary construction method: Design of a tube bundle. The tower is essentially a series of nine tubes, bound together. I think of it as a pack of cigarettes with each tube rising higher than the rest. Shorter tubes are 50 stories, the second group rises to 66, and the third set to 90, and the final to 110 stories. In the mechanical floors are extra trusses will act like belts wrapping around the building and assistance in the face of the forces of strong winds.


I was born in the Tower of the need for the company to strengthen its Sears. The original plan called for a much smaller tower, but he eventually persuaded the retailer to focus its staff from seven other buildings in the lower part of the building while leasing the rest to other companies. It is fortunate that Sears listened to the architects and developers, because it is not an understatement to call the result of one of the most important buildings on the face of the earth.


It also burns the financial wealth of the change, I moved out of this building and to the Office of squatting in the suburbs. By 2003 Sears had let the naming rights for the construction ends. It was not until 2009 that the team and Willis consolidating a number of regional offices in this building, and received the naming rights in the process.


Shortly thereafter, as part of a larger group at the level of renewal "on the Skydeck" observation, added four centuries a small monitor in the open air to the floor 103. Designed glass transparent "edges" by Skidmore, Owings & Merrill, one of the largest architectural firms designed the tower itself, which appeared in 1970. Each viewing platform extends outside of the tower a little over four feet, and constructed of three layers of half-inch thick glass with a capacity weight of five tons - two tons more than called for in the Construction Law in the city. Edges and retractable, and put it on the west side of the building, 1353 meters above ground level.

Height to tip of west antenna: 1,729 feet
Height to tip of east antenna: 1,709 feet
Height to roof: 1,450 feet, seven inches
Height to glass ledges: 1,353 feet
Official stories: 110
Missing floor: 109. The building owners count the roof as 109.
Disputed floor: The mechanical penthouse for the elevators. Some buildings count this, some do not. Sears Tower does.
Total floor space: 4,560,000 square feet
Rentable floor space: 3,800,000 square feet
Weight: 222,500 tons / 445,000,000 pounds
Caissons: 114 in bedrock 65 feet underground
Elevators: 104
Double-decker elevators: 14
Escalators: 15
Observatory elevators speed: 18.2 miles per hour
Windows: 16,100+
Property size: 2.96 acres
Parking spaces: 160
Plumbing: 25+ miles
Electrical: 1,500+ miles
Elevator cables: 80+miles