15 floor building height in meters

The world's tallest human-made structure is the 828-metre-tall (2,717 ft) Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of "tallest building in the world" and the tallest self-supported structure at its opening on January 9, 2010. Burj Khalifa was developed by Emaar properties, designed by Skidmore, Owings and Merrill and built by BESIX, Samsung Construction and Arabtec.[1] The second-tallest self-supporting structure and the tallest tower in the world is the Tokyo Skytree. The tallest guyed structure is the KVLY-TV mast at 1987 feet.

The Council on Tall Buildings and Urban Habitat, an organization that certifies buildings as the "World's Tallest", recognizes a building only if at least 49% of its height is made up of floor plates containing habitable floor area.[2] Structures that do not meet this criterion, such as the CN Tower, are defined as "towers".

There are dozens of radio and television broadcasting towers which measure over 600 metres (about 2,000 ft) in height, and only the tallest are recorded in publicly available information sources.

Debate over definition[edit]

The assessment of the height of artificial structures has been controversial. Because varying standards have been used by different organizations, the accepted height of these structures or buildings depends on which standards are accepted. The Council on Tall Buildings and Urban Habitat has changed its definitions over time. Some of the controversy regarding the definitions and assessment of tall structures and buildings has included the following:

• the definition of a structure, a building and a tower
• whether a structure, building or tower under construction should be included in any assessment
• whether a structure, building or tower has to be officially opened before it is assessed
• whether structures built in and rising above water should have their below-water height included in any assessment.
• whether a structure, building or tower that is guyed is assessed in the same category as self-supporting structures.

Within an accepted definition of a building further controversy has included the following factors:

• whether only habitable height of the building is considered
• whether communication towers with observation galleries should be considered "habitable" in this sense
• whether rooftop antennas, viewing platforms or any other architecture that does not form a habitable floor should be included in the assessment
• whether a floor built at a high level of a telecommunications or viewing tower should change the tower's definition to that of a "building"

Tallest structures[edit]

This category does not require the structure to be "officially" open, but does require it to be "topped out."

The tallest artificial structure is Burj Khalifa, a skyscraper in Dubai that reached 829.8 m (2,722 ft) in height on January 17, 2009.[3] By April 8, 2008 it had been built higher than the KVLY-TV mast in North Dakota, US.[4] That September it officially surpassed Poland's 646.38 m (2,120.7 ft) Warsaw radio mast, which stood from 1974 to 1991, to become the tallest structure ever built. Guyed lattice towers such as these masts had held the world height record since 1954.

The Petronius Platform stands 610 m (2,000 ft) off the sea floor, leading some, including Guinness World Records 2007, to claim it as the tallest freestanding structure in the world, until surpassed by the Burj Khalifa in 2010. However, it is debated whether underwater height should be counted, in the same manner as height below ground is ignored on buildings. The Troll A platform is 472 m (1,549 ft), without any part of that height being supported by wires. The tension-leg type of oil platform has even greater below-water heights with several examples more than 1,000 m (3,300 ft) deep. However, these platforms are not considered constant structures as the vast majority of their height is made up of the length of the tendons attaching the floating platforms to the sea floor. Despite this, Guinness World Records 2009 listed the Ursa tension leg platform as the tallest structure in the world with a total height of 1,306 m (4,285 ft). The Magnolia Tension-leg Platform in the Gulf of Mexico is even taller with a total height of 1,432 m (4,698 ft).

Taipei 101 in Taipei, Taiwan, set records in three of the four skyscraper categories at the time it opened in 2004; at the time the Burj Khalifa opened in 2010 it remained the world's tallest inhabited building 509.2 m (1,671 ft) as measured to its architectural height (spire). The height of its roof 449.2 m (1,474 ft) and highest occupied floor 439.2 m (1,441 ft) had been surpassed by the Shanghai World Financial Center with corresponding heights of 487 and 474 m (1,598 and 1,555 ft). Willis Tower (formerly Sears Tower) was the highest in the final category: the greatest height to top of antenna of any building in the world at 527 m (1,729 ft).

Burj Khalifa broke the height record in all four categories for completed buildings.

Due to the disagreements over how to measure height and classify structures, engineers have created various definitions for categories of buildings and other structures. One measure includes the absolute height of a building, another includes only spires and other permanent architectural features, but not antennas. The tradition of including the spire on top of a building and not including the antenna dates back to the rivalry between the Chrysler Building and 40 Wall Street. A modern-day example is that the antenna on top of Willis Tower (formerly Sears Tower) is not considered part of its architectural height, while the spires on top of the Petronas Twin Towers are counted.

Note: The following table is a list of the tallest completed structure in each of the structural categories below. For a list of structures by function see the list later in the article. There can only be one structure in each category, unless the tallest is the same for more than one structure in the same category.

There are some destroyed architectural structures which were taller than the tallest existing structure of their type. There are also destroyed structures omitted from this list that had been surpassed in height prior to being destroyed.

Tallest structure by function[edit]

* "Mixed-use" is defined as having three or more real estate uses (such as retail, office, hotel, etc.) that are physically and functionally integrated in a single property and are mutually supporting.[19]

Tallest buildings[edit]

Up until the late 1990s, the definition of “tallest building” was not altogether clear. It was generally understood to be the height of the building to the top of its architectural elements including spires, but not including "temporary" structures (such as antennas or flagpoles), which could be added or changed relatively easily without requiring major changes to the building's design. Other criteria for height measurement generally were not considered, which occasionally caused some controversy.

One historic case involved the building now famous for the Times Square Ball. Known as One Times Square (at 1475 Broadway in Midtown Manhattan), it was the headquarters for The New York Times, which gave Times Square its name. Completed in 1905, it reached a height of 364 feet (111 meters) to its roof, or 420 feet (130 meters) including its rooftop flagpole, which the Times hoped would give it a record high status but because a flagpole is not an integral architectural part of a building, One Times Square was not generally considered to be taller than the 390-foot-high (120 m) Park Row Building in Lower Manhattan, which was therefore still New York's tallest.[20]

A bigger controversy was the rivalry between two New York skyscrapers built in the Roaring Twenties—the Chrysler Building and 40 Wall Street. The latter was 927 feet (283 meters) tall, had a shorter pinnacle, and had a much higher top occupied floor (the second category in the 1996 criteria for tallest building).[21] In contrast, the Chrysler Building employed a very long 125-foot (38 m) spire secretly assembled inside the building to claim the title of world's tallest building with a total height of 1,048 feet (319 m), despite having a lower top occupied floor and a shorter height when both buildings' spires are not counted in their heights.[22] Although the architects of record for 40 Wall were H. Craig Severance and Yasuo Matsui, the firm of Shreve & Lamb (who also designed the Empire State Building) served as consulting architects. They wrote a newspaper article claiming that 40 Wall was actually the tallest, since it contained the world's highest usable floor. They pointed out that the observation deck of 40 Wall was nearly 100 feet (30 m) higher than the top floor of the Chrysler, whose surpassing spire was strictly ornamental and essentially inaccessible.[23] Despite the protest, the Chrysler Building was generally accepted as the tallest building in the world for almost a year, until it was surpassed by the Empire State Building’s 1,250 feet (380 meters) in 1931.

That was in turn surpassed by the 1,368-foot-high (417 m) twin towers of New York’s original World Trade Center in 1972, which were in turn surpassed by the Sears Tower in Chicago in 1974. Now called the Willis Tower (since 2009) it was 1,451 feet (442 meters) to its flat rooftop, or 1,518 feet (463 meters) including its original antennas.[24] But in 1978 One World Trade Center (commonly known as the north tower) attained a taller absolute height when it added its 360-foot (110 m) new broadcasting antenna, for a total height of 1,728 feet (527 meters). The WTC north tower maintained this height record (including its antenna) from 1978 until 2000, when the owners of the Willis Tower extended its broadcasting antennae for a total height of 1,729 feet (527 meters).[24] Thus the status of the Willis Tower as the “totally” tallest was restored in the face of a new threat looming in the Far East—the “Siamese Twins.”

The Petronas Towers remain the tallest twin towers in the world.

A major controversy erupted upon completion of the Petronas Towers in Kuala Lumpur, Malaysia in 1998. These twin towers, at 1,483 feet (452 meters), had a higher architectural height (spires, not antennas), but a lower absolute pinnacle height and a lower top occupied floor than the Willis Tower in Chicago. Counting buildings as structures with floors throughout, and with antenna masts excluded, the Willis was still considered the tallest at that time. Excluding their spires, which are 9 meters (30 feet) higher than the flat roof of Willis, the Petronas Towers are not taller than Willis. At their convention in Chicago, the Council on Tall Buildings and Urban Habitat (CTBUH) found the Willis Tower (without its antennas) to be the third-tallest building, and the Petronas Towers (with their spires) to be the world's two tallest buildings.[20]

Responding to the ensuing controversy, the CTBUH then revised their criteria and defined four categories in which the world's tallest building can be measured,[25] retaining the old criterion of height to architectural top, and adding three new categories:[20]

1. Height to Architectural Top (including spires and pinnacles, but not antennas, masts or flagpoles). This measurement is the most widely used and is used to define the rankings of the 100 Tallest Buildings in the World.
2. Highest Occupied Floor
3. Height to Top of Roof (omitted from criteria from November 2009 onwards)[26]
4. Height to Tip

The height-to-roof criterion was discontinued because relatively few modern tall buildings possess flat rooftops, making this criterion difficult to determine and measure.[27] The CTBUH has further clarified their definitions of building height, including specific criteria concerning subbasements and ground level entrances (height measured from lowest, significant, open-air, pedestrian entrance rather than from a previously undefined "main entrance"), building completion (must be topped out both structurally and architecturally, fully clad, and able to be occupied), condition of the highest occupied floor (must be continuously used by people living or working and be conditioned, thus including observation decks, but not mechanical floors) and other aspects of tall buildings.[27][28]

The height is measured from the level of the lowest, significant, open-air, pedestrian entrance. At the time, the Willis Tower held first place in the second and third categories, the Petronas Towers held the first category, and the original WTC north tower held the fourth (height to tip) category with its antenna.[20] In 2000, however, a new antenna mast was placed on the Willis Tower, giving it the record in the fourth category. On April 20, 2004, the 101-storey Taipei 101 in Taipei, Taiwan, was completed, taking the world record for the first three categories. On July 21, 2007, it was announced that Burj Khalifa in Dubai, UAE, had surpassed Taipei 101. Since its completion in early 2010, Burj Khalifa leads in all categories (the first building to do so) with its spire height of 2,722 feet (830 meters).

Before Burj Khalifa was completed, Willis Tower led in the height-to-tip category with 1,729 feet (527 meters) after its antenna was extended in 2000, making Willis Tower slightly taller height-to-tip than the WTC north tower's antenna that measured 1,728 feet (527 meters). After the September 11, 2001, attacks, the WTC became the world's tallest two buildings to be destroyed or demolished. They took that distinction from the Singer Building, which stood 612 feet (187 meters) tall until the late 1960s where One Liberty Plaza now stands right across Church Street from the WTC site.

A different superlative for skyscrapers is their number of floors. The original World Trade Center set that record at 110 in the early 1970s, and this was not surpassed until the Burj Khalifa opened in 2010.

Tall freestanding structures such as the CN Tower, the Ostankino Tower and the Oriental Pearl Tower are excluded from these categories because they are not "habitable buildings", which are defined as frame structures made with floors and walls throughout.[2]

Tallest freestanding structures on land[edit]

Freestanding structures must not be supported by guy wires, the sea or other types of support. It therefore does not include guyed masts, partially guyed towers and drilling platforms but does include towers, skyscrapers (pinnacle height) and chimneys. (See also history of tallest skyscrapers.)

The world's tallest freestanding structure on land is defined as the tallest self-supporting artificial structure that stands above ground. This definition is different from that of world's tallest building or world's tallest structure based on the percentage of the structure that is occupied and whether or not it is self-supporting or supported by exterior cables. Likewise, this definition does not count structures that are built underground or on the seabed, such as the Petronius Platform in the Gulf of Mexico. Visit world's tallest structure by category for a list of various other definitions.

The tallest freestanding structure on land is the Burj Khalifa in Dubai, United Arab Emirates. The building surpassed the height of the previous record holder, the 553.3 m (1,815 ft) CN Tower in Toronto, Ontario, on September 12, 2007. It was completed in 2010, with final height of 829.8 m (2,722 ft).

History[edit]

The following is a list of structures that have historically held the title as the tallest towers in the world.

How high is a 15 story building?

How many floors is 100 meters?

What is a 15 story building?

What is the height of a 10 story building?