List of tallest buildings
The international non-profit organization Council on Tall Buildings and Urban Habitat (CTBUH) was formed in 1969 and announces the title of "The World's Tallest Building" and sets the standards by which buildings are measured. It maintains a list of the 100 tallest completed buildings in the world. The organization currently ranks Burj Khalifa in Dubai as the tallest at . The CTBUH only recognizes buildings that are complete however, and some buildings included within the lists in this article are not considered finished by the CTBUH.
World Trade Center (1973–2001)
When completed in 1972, 1 World Trade Center became the tallest building in the world for two years, surpassing the Empire State Building after a 40-year reign. The North Tower stood tall and featured a telecommunications antenna or mast that was added at the top of the roof in 1978 and stood tall. With the -tall antenna/mast, the highest point of the North Tower reached . Chicago's Sears Tower, finished in , reached at the rooftop. Throughout their existence, the WTC towers had more floors (at 110) than any other building. This number was not surpassed until the advent of the Burj Khalifa, which opened in 2010. Each tower had a total mass of around 500,000 tons.