History of the world's tallest buildings
The buildings that were the tallest secular skyscrapers, which excludes religious buildings, were:
The list of tallest buildings is based on the default metric of the Council on Tall Buildings and Urban Habitat (CTBUH), that of measuring to the highest architectural element. Other criteria would generate a different list. Shanghai World Financial Center is not on the above list, but it surpassed Taipei 101 in 2008 to become the building with the highest occupied floor. Using the criteria of highest tip (including antennae), the World Trade Center in New York City was the world's tallest building from 1972 to 2000, until the Sears Tower in Chicago (which already had a higher occupied floor than the World Trade Center) had its antenna extended to give that building the world's tallest tip; a title it held until the 2010 completion of Burj Khalifa. Petronas Towers and Taipei 101 were never the world's tallest buildings by the highest–tip criteria.
World Trade Center (1973–2001)
One World Trade Center and Two World Trade Center, commonly the Twin Towers, the idea of which was brought up by Minoru Yamasaki, were designed as framed tube structures, which provided tenants with open floor plans, uninterrupted by columns or walls. They were the main buildings of the World Trade Center. The North Tower (One World Trade Center), the tallest building in the world at by the time of its completion, began construction in 1966 with the South Tower (2 World Trade Center); extensive use of prefabricated components helped to speed up the construction process, and the first tenants moved into the North Tower in December 1970, while it was still under construction. When completed in 1973, the South Tower, Two World Trade Center (the South Tower) became the second tallest building in the world at ; the South Tower's rooftop observation deck was high and its indoor observation deck was high. Each tower stood over high, and occupied about of the total of the site's land. During a press conference in 1973, Yamasaki was asked, "Why two 110-story buildings? Why not one 220-story building?" His tongue-in-cheek response was: "I didn't want to lose the human scale."