ⓘ Willis Tower is a skyscraper in Chicago, Illinois. Sears, Roebuck and Company paid for it to be built in August 1970. The building was finished in 1973. It was ..

Willis Tower

ⓘ Willis Tower

Willis Tower is a skyscraper in Chicago, Illinois. Sears, Roebuck and Company paid for it to be built in August 1970. The building was finished in 1973. It was the tallest building in the world from 1973 to 1996. It has 110 levels. From the ground to the roof it is 442 meters tall. It was designed by Fazlur Khan and Bruce Graham.

Willis Tower is the second-tallest building in the United States. It is the eighth-tallest freestanding structure in the world. It is the second tallest skyscraper in the Americas. It is one of the most popular tourist destinations in Chicago. More than one million people visit its observation deck every year.

Until July 16, 2009, the building was called Sears Tower. It was renamed after the Willis Group bought it.


1. History

In 1969, Sears, Roebuck & Company was the largest retailer in the world. It had thousands of workers in offices in the Chicago area. Sears managers decided to put all of those workers into one building. They wanted 3.000.000 square feet 280.000 square meters of space. Sears hired architects Skidmore, Owings & Merrill SOM to design one of the largest office buildings in the world. Architect Bruce Graham and structural engineer Fazlur Khan designed the building.

Sears and the City of Chicago approved the design. Steel was transported from South Chicago. The first steel was put in place in April 1971. The tower was completed in May 1973. It cost about US$150 million to build. That is equivalent to $800 million in 2014.

The building was built with a fire sprinkler system, even though it wasnt required at the time. There are about 40.000 sprinkler heads in the building. The sprinkler system cost $4 million.

In February 1982, two television antennas were added to the tower. That made the building 1.707 feet 520 meters tall. On June 5, 2000, the western antenna was made longer to improve reception of local NBC. That made the overall height 1.730 feet 527 meters

Before Willis Tower was completed, the tallest building in the world was the World Trade Center. In 1996, the Petronas Twin Towers in Kuala Lumpur, Malaysia became the worlds tallest buildings.


1.1. History Name rights

The buildings name was changed to Willis Tower in July 2009 after the Willis Group bought the skyscraper. Time magazine called the name change one of the top 10 worst corporate name changes. An online petition was created to change their decision. The naming rights issue continued into 2013. It began when a news reporter of the Chicago Tribune said in 2013 that "Were stubborn about such things. This month marked four years since the former Sears Tower was re-christened Willis Tower, and the new name has yet to stick."

In 2015 the Blackstone company bought the building. In 2017 it began an extensive repurposing of the lower part of the building.


2. Design

Skidmore architects designed Willis Tower to have large floors of 55.000 square feet 5.100 square meters in the lower part of the building. They got the idea for the design from an advertisement for a package of cigarettes.


From the ground to the top of the taller antenna, Willis Tower is 1.729 feet 527 meters tall. It leans about 4 inches 10 centimeters towards the west because of the unequal loads on its foundation. Willis Tower is the second tallest skyscraper in North America. The observatory elevators in the tower are the fastest in the world at 1.600 feet 490 meters per minute. With clear weather, four states can be seen from the observation deck: Michigan, Indiana, Illinois, and Wisconsin.

On November 8, 2013, architects in Chicago and New York City started talking about the height of the One World Trade Center. They were saying that Willis Tower might be taller. On November 12, it was confirmed that One World Trade Center is taller than the Willis Tower.


3. The Skydeck

Willis Tower has an observation deck. It is called the Skydeck. It opened on June 22, 1974. It is on the 103rd floor of the building. It is 1.353 feet 412 meters high. It is one of the most famous tourist attractions in Chicago. The observation deck is the highest public viewing area in the United States. Tourists on the Skydeck can feel the building moving on windy days. They can see the plains of Illinois and across Lake Michigan. Elevators take tourists to the top in about 60 seconds. People on the elevator can feel air pressure changes during the ride.

In January 2009, Willis Towers owners began making major changes to the Skydeck. They added retractable glass balconies. The balconies extend about 4 feet 1.2 meters from the tower. They allow visitors to look through the floor to the street below. The boxes can hold up to 5 short tons 4.5 metric tons of weight. They were opened to the public on July 2, 2009.


4. Awards

The building has been given ENERGY STAR certification by the U.S. Environmental Protection Agency EPA. This is for being in the top quarter of buildings of its type in the U.S. in terms of energy efficiency.


5. Other websites

  • – Willis Tower
  • Chicago Skydeck website Archived 2009-07-22 at the Wayback Machine
  • - Willis Tower
  • Official website
  • A view from 103rd floor of the tower
  • the USA behind the One World Trade Center and the Willis Tower It is the second tallest tower in Chicago. List of tallest buildings in Chicago List
  • 2018. These plans make the building 29 feet 8.8 m shorter than the Willis Tower the city s tallest. On mid - October 2018, the Chicago Plan Commission
  • the One World Trade Center and the Willis Tower They were saying that there was a possibility that the Willis Tower is taller than the One World Trade
  • and his business partner Fazlur Khan are well known for designing the Willis Tower and the 875 North Michigan Avenue, both in Chicago, Illinois. Graham
  • John Hancock Center 1969, second tallest in the world when built Willis Tower 1973, tallest in the world for over twenty years and Burj Khalifa
  • underground, buried beneath streets and skyscrapers. It is located near the Willis Tower Media related to Chicago Union Station at Wikimedia Commons This short
  • The Petronas Towers are two very tall skyscrapers in Kuala Lumpur, Malaysia. They were the tallest buildings in the world until 2004, but still remain
  • 828 m 2, 717 ft previously CN Tower 553.3 m 1, 815 ft Building with most floors: 160 previously Willis Tower 108 World s highest elevator installation
  • Petronas Towers with their spires, are thus ranked higher than the Willis Tower formerly the Sears Tower with its antennas, despite the Petronas Towers s
  • near the southern rim of Lake Michigan 10 miles south of downtown. The Willis Tower and the Hancock Building were built from South Chicago steel. South Chicago