Skyscraper

For other uses, see Skyscraper (disambiguation).

File:Burj1003.jpg

Burj Dubai is currently under construction and will be the tallest skyscraper in the World, dominating all height-related ranking criteria.

A skyscraper is a tall, continuously habitable building. There is no official definition nor height above which a building may clearly be classified as a skyscraper. Most cities define the term empirically; even a building of Template:M to ft may be considered a skyscraper if it protrudes above its built environment and changes the overall skyline.

Definition

Taipei 101 is the world's tallest completed skyscraper.

The word "skyscraper" originally was a nautical term referring to a tall mast or its main sail on a sailing ship. The term was first applied to buildings in the late 19th century as a result of public amazement at the tall buildings being built in Chicago and New York City. The traditional definition of a skyscraper began with the "first skyscraper", a steel-framed ten storey building. Chicago's now demolished ten storey steel-framed Home Insurance Building (1885) is generally accepted as the "first skyscraper".

The structural definition of the word skyscraper was refined later by architectural historians, based on engineering developments of the 1880s that had enabled construction of tall multi-storey buildings. This definition was based on the steel skeleton—as opposed to constructions of load-bearing masonry, which passed their practical limit in 1891 with Chicago's Monadnock Building. Philadelphia's City Hall, completed in 1901, still holds claim as the world's tallest load-bearing masonry structure at 167 m (548 ft). The steel frame developed in stages of increasing self-sufficiency, with several buildings in Chicago and New York advancing the technology that allowed the steel frame to carry a building on its own. Today, however, many of the tallest skyscrapers are built almost entirely with reinforced concrete. Pumps and storage tanks maintain water pressure at the top of skyscrapers.

A loose convention in the United States and Europe now draws the lower limit of a skyscraper at 150 meters (500 ft). A skyscraper taller than 300 meters (984 ft) may be referred to as supertall. Shorter buildings are still sometimes referred to as skyscrapers if they appear to dominate their surroundings.

The somewhat arbitrary term skyscraper should not be confused with the slightly less arbitrary term highrise, defined by the Emporis Standards Committee as "...a multi-storey structure with at least 12 floors or 35 meters (115 feet) in height." Some structural engineers define a highrise as any vertical construction for which wind is a more significant load factor than earthquake or weight. Note that this criterion fits not only high rises but some other tall structures, such as towers.

The word skyscraper often carries a connotation of pride and achievement. The skyscraper, in name and social function, is a modern expression of the age-old symbol of the world center or axis mundi: a pillar that connects earth to heaven and the four compass directions to one another.

History

Before the 19th century

The Great Pyramid of Giza, circa 2560 BC, was 146 metres tall and its height was unsurpassed until at least the 14th century AD.

The Two Towers of Bologna in the 12th century reached 97.2 metres in height.

The 16th-century city of Shibam consisted entirely of over 500 high-rise tower houses.

Modern skyscrapers are built with materials such as steel, glass, reinforced concrete and granite, and routinely utilize mechanical equipment such as water pumps and elevators. Until the 19th century, buildings of over six stories were rare, as having great numbers of stairs to climb was impractical for inhabitants, and water pressure was usually insufficient to supply running water above 50 m (164 ft).

The tallest building in ancient times was the Great Pyramid of Giza in ancient Egypt, which was 146 metres (479 ft) tall and was built in the 26th century BC. Its height was not surpassed for thousands of years, possibly until the 14th century AD with the construction of the Lincoln Cathedral (though its height is disputed), which in turn was not surpassed in height until the Washington Monument in 1884. However, being uninhabited buildings, none of these buildings actually complies to the definition of a skyscraper.

High-rise apartment building already flourished in antiquity: ancient Roman insulae in Rome and other imperial cities reached up to 10 and more stories, some with more than 200 stairs. Several emperors, beginning with Augustus (r. 30 BC-14 AD), attempted to establish limits of 20-25 m for multi-story buildings, but met with only limited success. The lower floors were typically occupied by either shops or wealthy families, while the upper stories were rented out to the lower classes. Surviving Oxyrhynchus Papyri indicate that seven story buildings even existed in provincial towns, such as in 3rd century AD Hermopolis in Roman Egypt.

The skyline of many important medieval cities had large numbers of high-rise urban towers. These towers were built for defensive but also representative functions by the wealthiest families. The residential Towers of Bologna in the 12th century, for example, numbered between 80 to 100 at a time, the largest of which (known as the "Two Towers") rise to 97.2 metres (319 ft). In Florence, a law of 1251 decreed that all urban buildings should be reduced to a height of less than 26 m, the regulation immediately put into effect. Even medium-sized towns at the time such as San Gimignano are known to have featured 72 towers up to 51 m height.

The medieval Egyptian city of Fustat housed many high-rise residential buildings, which Al-Muqaddasi in the 10th century described as resembling minarets. Nasir Khusraw in the early 11th century described some of them rising up to 14 stories, with roof gardens on the top storey complete with ox-drawn water wheels for irrigating them. Cairo in the 16th century had high-rise apartment buildings where the two lower floors were for commercial and storage purposes and the multiple stories above them were rented out to tenants. An early example of a city consisting entirely of high-rise housing is the 16th-century city of Shibam in Yemen. Shibam was made up of over 500 tower houses, each one rising 5 to 11 storeys high, with each floor being an apartment occupied by a single family. The city was built in this way in order to protect it from Bedouin attacks. Shibam still has the tallest mudbrick buildings in the world, with many of them over 100 feet (30 m) high, and the tallest of them (a minaret) standing at over 175 feet (53 m).

An early modern example of high-rise housing was in 17th-century Edinburgh, Scotland, where a defensive city wall defined the boundaries of the city. Due to the restricted land area available for development, the houses increased in height instead. Buildings of 11 stories were common, and there are records of buildings as high as 14 stories. Many of the stone-built structures can still be seen today in the old town of Edinburgh. The oldest iron framed building in the world is The Flaxmill (also locally known as the "Maltings"), in Shrewsbury, England. Built in 1797, it is seen as the "grandfather of skyscrapers” due to its fireproof combination of cast iron columns and cast iron beams developed into the modern steel frame that made modern skyscrapers possible. Unfortunately, it lies derelict and needs much investment to keep it standing. On 31 March 2005, it was announced that English Heritage would buy the Flaxmill so that it could be redeveloped.

Early skyscrapers

The first skyscraper was the ten-storey Home Insurance Building in Chicago, built in 1884–1885. While its height is not considered unusual or very impressive today, the architect, Major William Le Baron Jenney, created the first load-bearing structural frame. In this building, a steel frame supported the entire weight of the walls, instead of load-bearing walls carrying the weight of the building, which was the usual method. This development led to the "Chicago skeleton" form of construction. After Jenney's accomplishment the sky was truly the limit as far as building was concerned.

Sullivan's Wainwright Building building in St. Louis, 1891, was the first steel frame building with soaring vertical bands to emphasize the height of the building, and is, therefore, considered by some to be the first true skyscraper.

The United Kingdom also had its share of early skyscrapers. The first building to fit the engineering definition, meanwhile, was the then largest hotel in the world, the Grand Midland Hotel, now known as St Pancras Chambers in London, opened in 1873 with a clock tower 82 metres (269 ft) in height. The 12-floor Shell Mex House in London, at 58 metres (190 ft), was completed a year after the Home Insurance Building and managed to beat it in both height and floor count. 1877 saw the opening of the Gothic revival style Manchester Town Hall by Alfred Waterhouse. Its 87-metre-high clock and bell tower dominated that city's skyline for almost a century.

Built in 1931, The Empire State Building in New York City is one of the oldest, yet tallest skyscrapers.

Most early skyscrapers emerged in the land-strapped areas of Chicago, London, and New York toward the end of the 19th century. A land boom in Melbourne, Australia between 1888-1891 spurred the creation of a significant number of early skyscrapers, though none of these were steel reinforced and few remain today and height limits and fire restrictions were later introduced. London builders soon found building heights limited due to a complaint from Queen Victoria, rules that continued to exist with few exceptions until the 1950s; concerns about aesthetics and fire safety had likewise hampered the development of skyscrapers across continental Europe for the first half of the twentieth century (with the notable exceptions of the 26-storey Boerentoren in Antwerp, Belgium, built in 1932, and the 31-storey Torre Piacentini in Genoa, Italy, built in 1940). After an early competition between New York City and Chicago for the world's tallest building, New York took a firm lead by 1895 with the completion of the American Surety Building. Developers in Chicago also found themselves hampered by laws limiting height to about 40 stories, leaving New York to hold the title of tallest building for many years. New York City developers then competed among themselves, with successively taller buildings claiming the title of "world's tallest" in the 1920s and early 1930s, culminating with the completion of the Chrysler Building in 1930 and the Empire State Building in 1931, the world's tallest building for forty years.

Modern skyscrapers

The iconic World Trade Center twin towers were destroyed in 2001.

The Sears Tower in Chicago was the tallest building from 1974 to 1998, and remains the tallest in the US.

The Petronas Twin Towers, the world's tallest twin towers.

The Commerzbank Tower in Frankfurt/Germany is the tallest completed skyscraper in the European Union.

30 St Mary Axe in London, United Kingdom is an example of a modern environmentally friendly skyscraper.

From the 1930s onwards, skyscrapers also began to appear in Latin America (São Paulo, Caracas, Mexico City) and in Asia (Tokyo, Shanghai, Hong Kong, Singapore, Mumbai, Jakarta, Kuala Lumpur, Taipei, Bangkok). Immediately after World War II, the Soviet Union planned eight massive skyscrapers dubbed "Stalin Towers" for Moscow; seven of these were eventually built. The rest of Europe also slowly began to permit skyscrapers, starting with Madrid, in Spain, during the 1950s. Finally, skyscrapers also began to appear in Africa, the Middle East and Oceania (mainly Australia) from the late 1950s and early 1960s.

Still today no city in the world has more completed individual free-standing buildings over 492 ft (150 m) than New York City.. Hong Kong comes in with the most in the entire world, if one counts individually the multiple towers that rise from a common podium (as Emporis does), in buildings that rise several stories as a single structure before splitting into two or more columns of floors. The number of skyscrapers in Hong Kong will continue to increase, due to a prolonged highrise building boom and high demand for office and housing space in the area. A new building complex in Kowloon contains several mixed-use towers (hotel-shops-residential) and one of them will be 118 stories tall.

Chicago's skyline could not grow any further due to the heavy costs of constructing high-rise skyscrapers until the early 1960s, when structural engineer Fazlur Khan realized that the rigid steel frame structure that had "dominated tall building design and construction so long was not the only system fitting for tall buildings", marking "the beginning of a new era of skyscraper revolution in terms of multiple structural systems." His central innovation in skyscraper design and construction was the idea of the "tube" structural system, including the "framed tube", "trussed tube", and "bundled tube". These systems allowed far greater economic efficiency, and also allowed efficient skyscrapers to take on various shapes, no longer needing to be box-shaped. Over the next fifteen years, many towers were built by Khan and the "Second Chicago School", including the massive 442-meter (1,451-foot) Sears Tower, leading to its current number of buildings over 492 ft. Chicago is currently undergoing an epic construction boom that will greatly add to the city's skyline. Since 2000, at least 40 buildings at a minimum of 50 stories high have been built. The Chicago Spire, Trump International Hotel and Tower, Waterview Tower, Mandarin Oriental Tower, 29-39 South LaSalle, Park Michigan, and Aqua are some of the more notable projects currently underway in the city that invented the skyscraper. Chicago, Hong Kong, and New York City, otherwise known as the "the big three," are recognized in most architectural circles as having the most compelling skylines in the world. Other large cities that are currently experiencing major building booms involving skyscrapers include Shanghai in China, Dubai in the United Arab Emirates, and Miami, which now is third in the United States.

History of tallest skyscrapers

At the beginning of the 20th century, New York City was a center for the Beaux-Arts architectural movement, attracting the talents of such great architects as Stanford White and Carrere and Hastings. As better construction and engineering technology become available as the century progressed, New York became the focal point of the competition for the tallest building in the world. The city's striking skyline has been composed of numerous and varied skyscrapers, many of which are icons of 20th century architecture:

• The Flatiron Building, standing 285 ft (87 m) high, was one of the tallest buildings in the city upon its completion in 1902, made possible by its steel skeleton. It was one of the first buildings designed with a steel framework, and to achieve this height with other construction methods of that time would have been very difficult.

• The Woolworth Building, a neo-Gothic "Cathedral of Commerce" overlooking City Hall, was designed by Cass Gilbert. At 792 feet (241 m), it became the world's tallest building upon its completion in 1913, an honor it retained until 1930, when it was overtaken by 40 Wall Street.

• That same year, the Chrysler Building took the lead as the tallest building in the world, scraping the sky at 1,046 feet (319 m). Designed by William Van Alen, an art deco masterpiece with an exterior crafted of brick, the Chrysler Building continues to be a favorite of New Yorkers to this day.

• The Empire State Building, the first building to have more than 100 floors (it has 102), was completed the following year. It was designed by Shreve, Lamb and Harmon in the contemporary Art Deco style. The tower takes its name from the nickname of New York State. Upon its completion in 1931, it took the top spot as tallest building, and at 1,472 feet (448 m) to the very top of the antenna, towered above all other buildings until 1973.

• When the World Trade Center towers were completed in 1973 many felt them to be sterile monstrosities even though they were the world's tallest buildings at that time. But most New Yorkers became fond of "The Twin Towers", and with the loss of lives in the September 11, 2001 terrorist attacks there came great sadness for the loss of the buildings. The Empire State Building again became the tallest building in New York City.

• The Sears Tower was completed in 1974, one year after the World Trade Center, and surpassed it as the world's tallest building. It was the first building to emply the "bundled tube" structural system, designed by Fazlur Khan. The building was not surpassed in height until the Petronas Towers was constructed in 1998, but remained the tallest in some categories until the Burj Dubai, currently under construction, surpassed it in all categories.

Momentum in setting records passed from the United States to other nations in 1997 with the opening of the Petronas Twin Towers in Kuala Lumpur, Malaysia. The record for world's tallest building remained in Asia with the opening of Taipei 101 in Taipei, Taiwan, in 2004. A number of architectural records, including that of the world's tallest building, will reside in the Middle East from 2009 with the opening of the Burj Dubai in Dubai, UAE.

With this geographical transition a change can be seen in the approach to skyscraper design. For much of the twentieth century large buildings such as the Sears Tower and World Trade Center (New York) took the form of simple geometrical shapes. They were designed as large boxes. This reflected the "international style" or modernist philosophy shaped by Bauhaus architects early in the century. By the 1990s skyscraper design began to exhibit postmodernist influences. The newest record setters, though modern, incorporate traditional architectural features associated with the part of the world where they stand. Taipei 101 recalls the traditions of Asian pagoda architecture even as the Burj Dubai incorporates motifs from traditional Arabic art. The result in each case is a building that does not look equally at home in any skyline in any city in the world, but a building that reflects its own continent and culture.

For current rankings of skyscrapers by height, see List of tallest buildings in the world.

The following list measures height of the roof. The more common gauge is the highest architectural detail; such ranking would have included Petronas Towers, built in 1998. See List of tallest buildings in the world for details.

Built	Building	City	Country	Roof		Floors	Pinnacle		Current status
1873	Equitable Life Building	New York	United States	142 ft	43 m	8			Demolished
1889	Auditorium Building	Chicago	United States	269 ft	82 m	17	349 ft	106 m	Standing
1890	New York World Building	New York City	United States	309 ft	94 m	20	349 ft	106 m	Demolished
1894	Manhattan Life Insurance Building	New York City	United States	348 ft	106 m	18			Demolished
1899	Park Row Building	New York City	United States	391 ft	119 m	30			Standing
1901	Philadelphia City Hall	Philadelphia	United States	511 ft	155.8 m	9	548 ft	167 m	Standing
1908	Singer Building	New York City	United States	612 ft	187 m	47			Demolished
1909	Met Life Tower	New York City	United States	700 ft	213 m	50			Standing
1913	Woolworth Building	New York City	United States	792 ft	241 m	57			Standing
1930	40 Wall Street	New York City	United States			70	927 ft	283 m	Standing
1930	Chrysler Building	New York City	United States	925 ft	282 m	77	1,046 ft	319 m	Standing
1931	Empire State Building	New York City	United States	1,250 ft	381 m	102	1,472 ft	449 m	Standing
1972	World Trade Center (North tower)	New York City	United States	1,368 ft	417 m	110	1,727 ft	526.3 m	Destroyed
1974	Sears Tower	Chicago	United States	1,451 ft	442 m	108	1,729 ft	527 m	Standing
2003	Taipei 101	Taipei City	Taiwan	1,474 ft	448 m	101	1,671 ft	509 m	Standing
2009	Burj Dubai	Dubai	United Arab Emirates	2,684 ft	818 m	162	2,684 ft	818 m	Incomplete

Source: emporis.com DEFINITION: To graze (of flocks), to pasture, tend (flocks). rayah, from Arabic racya, flock, parish, subjects, a subject, from rac, to graze, pasture, tend.

The American Heritage® Dictionary of the English Language, Fourth Edition. Copyright © 2000 by Houghton Mifflin Company. Published by the Houghton Mifflin Company. All rights reserved. www.ASHTON.com www.IKEA.com www.NICEIC.com www.summerfairolympia.com 0208 511 4040. TOTTENHAM Hale, Newham, Westminster, Hammersmith, Wembley. Edinburgh Malboro.

Today

File:Freedom Tower New.jpg

An artist's rendering of the Freedom Tower, currently under construction in New York.

Nighttime rendition of Nakheel Tower.

An artist's rendering of Russia Tower.

Today, skyscrapers are an increasingly common sight where land is scarce, as in the centres of big cities, because they provide such a high ratio of rentable floor space per unit area of land. But they are built not just for economy of space. Like temples and palaces of the past, skyscrapers are considered symbols of a city's economic power. Not only do they define the skyline, they help to define the city's identity.

Supertall towers

An interesting phenomena in the design of tall buildings has emerged recently in the Middle East with new extremely challenging proposals for supertall towers of heights exceeding one kilometer, such as Nakheel Tower to be built in Dubai of the United Arab Emirates. With its announcement, the developer, Nakheel, intends to overtake the tallest structure in the world currently under construction in the same city of Dubai: the Burj Dubai. Other supertall towers are also proposed as new iconic buildings in the Middle East such as The Mile Tower to be built in Jeddah, KSA and Burj Mubarak Al Kabir in Kuwait. These distinctively supertall towers are different from what have been normally identified as skyscrapers, as they create exceptional challenges and, arguably, represent a new architectural paradigm.

Future skyscrapers

The following skyscrapers are either approved or due to be completed in the near future:

• Construction of the Burj Dubai is taking place in Dubai. Its exact height is expected to be 818 m (2,684 ft) high, making it the tallest building in the world. The Burj Dubai is due to be completed in June 2009.

• Construction of the Shanghai Tower started on 29 November 2008. The tower will be 632 m (2,073 ft) high and have 127 floors. The building will feature a glass curtain wall and nine indoor gardens when it is completed in 2014.

• Construction has started for a skyscraper in Moscow to be completed in 2012. The Russia Tower, standing at 612 m (2,008 ft) with 118 floors, it will be the tallest building in Europe when completed. Also it will be the tallest naturally ventilated building in the World.

• Construction has started for a 610 m (2,001 ft) skyscraper in Chicago, is estimated to be completed in 2012. The Chicago Spire with 150 floors, will be the second tallest residential building in the world. Designed by Santiago Calatrava, it will also hold the title of North America's tallest free-standing structure.

• The Freedom Tower is now under construction and is the tallest tower comprising the redevelopment of the site of the former World Trade Center following the attacks of September 11, 2001. Its antenna will reach a height of 541.4 m (1,776 ft), a height representing the year of the United States Declaration of Independence.

• The Port Tower is a building planned for Karachi, the financial capital of Pakistan, with the collaboration of local and foreign investors, in association with the Karachi Port Trust. When completed, the new structure will be 1,947 ft (593 m) high. The height of the tower has a special significance, representing the year Pakistan gained independence.

• The APIIC Tower is a building planned for Hyderabad, India. At 450 m (1,476 ft) it would be the tallest building in South Asia upon completion in 2010.

• The 318 m (1,043 ft) Tour Generali in Paris La Défense, scheduled to be completed in 2011, is an entirely green building office skyscraper that is set to be the tallest building in Paris and in the European Union.

• Construction is expected to start in January 2009, for the Shard London Bridge, also known as the Shard of Glass. At 310 m (1,017 ft), it is set to be the tallest building in London and the United Kingdom and the second tallest in the European Union after the Tour Generali in Paris when completed in 2012.

Sustainability

The skyscraper as a concept is a product of the industrialized age, made possible by cheap energy and raw materials. The amount of steel, concrete and glass needed to construct a skyscraper is vast, and these materials represent a great deal of embodied energy. Tall skyscrapers are very heavy, which means that they must be built on a sturdier foundation than would be required for shorter, lighter buildings. Building materials must also be lifted to the top of a skyscraper during construction, requiring more energy than would be necessary at lower heights. Furthermore, a skyscraper consumes a lot of electricity because potable and non-potable water must be pumped to the highest occupied floors, skyscrapers are usually designed to be mechanically ventilated, elevators are generally used instead of stairs, and natural lighting cannot be utilized in rooms far from the windows and the windowless spaces such as elevators, bathrooms and stairwells.

Despite these costs, the size of skyscrapers allows for high-density work and living spaces, reducing the amount of land given over to human development. Mass transit and commercial transport are economically and environmentally more efficient when serving high-density development than suburban or rural development. Also, the total energy expended towards waste disposal and climate control is relatively lower for a given number of people occupying a skyscraper than that same number of people occupying modern housing.

Quotations

"What is the chief characteristic of the tall office building? It is lofty. It must be tall. The force and power of altitude must be in it, the glory and pride of exaltation must be in it. It must be every inch a proud and soaring thing, rising in sheer exaltation that from bottom to top it is a unit without a single dissenting line."

—Louis Sullivan's The Tall Office Building Artistically Considered (1896)

References

• Skyscrapers: Form and Function, by David Bennett, Simon & Schuster, 1995.

See also

• List of tallest buildings in the world
• List of tallest buildings and structures in the world
• Emporis Skyscraper Award
• Skyline
• Skyscrapers in film
• Skyscraper design and construction

External links

• Historical photos of skyscrapers in New York City
• Skyscraper Museum
• Tallest Building in the World
• Skyscrapers and sequoias in the USA
• SkyscraperPage Technical information and diagrams
• SkyScrapers.org High Resolution skyscraper illustrations.
• Skyscrapers at Curlie
• 1880s "skyscraper" citations from word researcher Barry Popik.