World's tallest structures: Encyclopedia II - World's tallest structures - Tallest buildings

World's tallest structures - Tallest buildings

Up until 1998 the tallest building status was essentially uncontested. Counting buildings as structures with floors throughout, New York City's World Trade Center was the tallest including the antennas, Sears Tower in Chicago excluding the antennas. As antennas were usually excluded, Sears Tower was counted as the tallest. When Petronas Twin Towers in Kuala Lumpur, Malaysia was built, some felt that the "spire" extending to 9 meters higher than the roof of the Sears Tower was just added to "cheat" its way into the spot as tallest building. Excluding the spire, the Petronas Towers were not taller than the Sears Tower. Therefore, before the Petronas Towers were completed, the Council on Tall Buildings and Urban Habitat defined four categories in which the "world's tallest building" can be measured:

1. Height to the structural or architectural top (including spires and pinnacles, but not antennas, masts or flagpoles)
2. Height to the highest occupied floor
3. Height to the top of the roof
4. Height to the top of antenna

The height is measured from the sidewalk level of the main entrance. In all of these categories, Sears Tower had held the top spot. After Petronas was built, Sears Tower became second in the first category only.

On April 20, 2004, the Taipei 101 in Taipei, Taiwan was completed. Its completion gave it the record for the first category.

Today, the Taipei 101 leads in the first category with 508 m (1,667 ft); in the second category with an occupied floor at 438 m (1,437 ft); and in the third category with 448 m (1,470 ft). The first category was formerly held by the Petronas Twin Towers with 452 m (1,483 ft), and before that by Sears Tower with 443 m (1,448 ft). The second category was held by the Sears Tower, with 435 m (1,431 ft). The third category was formerly held by the Sears Tower with 442 m (1,445 ft).

The Sears Tower still leads in the fourth category with 527 m (1,730 ft), previously held by the World Trade Center until the extension of the Chicago tower's western broadcast antenna in 2000, over a year prior to the Trade Center's destruction in 2001. Its antenna included, 1 World Trade Center measured 526 m (1,727 ft). The World Trade Center became the world's tallest buildings to be demolished–indeed, its site entered the record books twice on September 11, 2001, in that category, replacing the Singer Building, which once stood a block from the WTC site.

The Ostankino Tower and the CN Tower are excluded from these categories because they are not "habitable buildings", which are defined as frame structures made with floors and walls throughout.

History of Record Holders in each CTBUH category

Adapted from the Wikipedia article "Tallest buildings", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki