Architecture of Chicago a new structural system of framed tubes in skyscraper design and construction. The first building to apply the tube-frame construction was the DeWitt-Chestnut Apartment Building which Khan designed and was completed in Chicago by 1966. This laid the foundations for the tube structures of many other later skyscrapers, including his own constructions of the John Hancock Center and Willis Tower (then named the Sears Tower) in Chicago and can be seen in the construction of the World Trade Center, Petronas Towers, Jin Mao Building, and most other supertall skyscrapers since the 1960s. Willis Tower would be the world's tallest building
Century Tower (Chicago) is listed in the National Register of Historic Places. This building has formerly been named: Century Tower (Chicago) The Century Tower Condominiums, formerly known as the Trustees System Service Building, is a historic building located at 182 West Lake Street in the Loop in Chicago, Illinois. The building was designed in 1929 and completed in 1930; at the time of its completion, it was the tallest reinforced concrete building in the world. Its original tenant and namesake was the Trustees Service System, a bank that specialized in consumer loans. Architects Thielbar and Fugard designed the building in the Art Deco