Skyscraper

The Torre Mayor in Mexico, is the tallest building in Latin America.

File:Emirates Towers 2005.jpg

Emirates Towers in Dubai, currently the tallest and fourth tallest completed skyscrapers in the Middle East

The Freedom Tower, under construction in New York, will be the tallest building in the U.S. when completed in 2010, standing at 541 m (1,776 ft) in height. However, the Chicago Spire, expected to be completed by 2010, is expected to stand at 610 m (2,000 ft)

The U.S. Bank Tower (middle) in Los Angeles, California is the tallest building west of the Mississippi River.

A skyscraper is a very tall, continuously habitable building. There is no official definition or a precise cutoff height above which a building may clearly be classified as a skyscraper. However, as per usual practice in most cities, the definition is used empirically, depending on the relative impact of the shape of a building to a city's overall skyline. Thus, depending on the average height of the rest of the buildings and/ or structures in a city, even a building of 80 meters height (approximately 262 ft) may be considered a skyscraper provided that it clearly stands out above its surrounding built environment and significantly changes the overall skyline of that particular city.

The word skyscraper originally referred to a nautical term 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, Detroit and New York City.

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-story 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 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. In the United States, the supertall convention is 100 stories, which is equal to 1,000 feet. 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 high-rise building is a multi-story structure with at least 12 floors or 35 meters (115 feet) in height."^[1] All skyscrapers are highrises, but only the tallest highrises are skyscrapers. Habitability separates skyscrapers from towers and masts. Some structural engineers define a highrise as any vertical construction for which wind is a more significant load factor than weight. Note that this criterion fits not only highrises 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.^[2]

History

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 Template:Unit m. However, despite the lack of sanitation, the first highrise housing dates back to the 1600s in some places. In Edinburgh, Scotland, for example, 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.

The first skyscraper was the ten-story 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, 1890, 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.

Most early skyscrapers emerged in the land-strapped areas of Chicago, London, and New York toward the end of the 19th century. 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 storeys, 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. 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).

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.^[3]. Hong Kong comes in with the most in the entire world,^[4] 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 was not allowed to grow until the height limits were relaxed in 1960; over the next fifteen years many towers were built, including the massive 442-meter (1,451-foot) Sears Tower,^[5] 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.^[6]^[7] The Chicago Spire, Trump International Hotel and Tower (Chicago), 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 and Dubai in the United Arab Emirates.

Today, skyscrapers are an increasingly common sight where land is scarce, as in the centres of big cities, because of the high ratio of rentable floor space per area of land. Skyscrapers, like temples and palaces in the past, are considered symbols of a city's economic power.

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). More impressive than its height is the building's design, 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 after the initial horror for the loss of life in the September 11, 2001 terrorist attacks there came great sadness for the loss of the buildings. The Empire State Building is again the tallest building in New York City.

Momentum in setting records passed from the Unites 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 will likely reside in the Middle East in 2008 or 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 and the Petronas Towers recall the traditions of Asian pagoda architecture even as the Burj Dubai incorporates motifs from traditional Arab 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 skyscrapers.

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 skyscrapers for details.

Built	Building	City	Country	Roof		Floors	Pinnacle		Current status
1873	Equitable Life Building	New York	U.S.	142 ft	43 m	8			Demolished
1889	Auditorium Building	Chicago	U.S.	269 ft	82 m	17	349 ft	106 m	Standing
1890	New York World Building	New York City	U.S.	309 ft	94 m	20	349 ft	106 m	Demolished
1894	Manhattan Life Insurance Building	New York City	U.S.	348 ft	106 m	18			Demolished
1899	Park Row Building	New York City	U.S.	391 ft	119 m	30			Standing
1901	Philadelphia City Hall	Philadelphia	U.S.			9	548 ft	167 m	Standing
1908	Singer Building	New York City	U.S.	612 ft	187 m	47			Demolished
1909	Met Life Tower	New York City	U.S.	700 ft	213 m	50			Standing
1913	Woolworth Building	New York City	U.S.	792 ft	241 m	57			Standing
1930	40 Wall Street	New York City	U.S.			70	927 ft	283 m	Standing
1930	Chrysler Building	New York City	U.S.	925 ft	282 m	77	1,046 ft	319 m	Standing
1931	Empire State Building	New York City	U.S.	1,250 ft	381 m	102	1,472 ft	449 m	Standing
1972	World Trade Center (North tower)	New York City	U.S.	1,368 ft	417 m	110	1,732 ft	528 m	Demolished
1974	Sears Tower	Chicago	U.S.	1,451 ft	442 m	108	1,729 ft	527 m	Standing
1998	Petronas Towers	Kuala Lumpur	Malaysia	1,322 ft	403 m	88	1,483 ft	452 m	Standing
2003	Taipei 101	Taipei City	Taiwan	1,474 ft	448 m	101	1,671 ft	509 m	Standing

Source: emporis.com

Future

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

Construction of the Burj Dubai is taking place in Dubai. Its exact future height is kept secret, but it is expected to become at least Template:Unit m high, making it the tallest building in the world. The Burj Dubai is due to be completed in June 2009.

Standing at Template:Unit m and scheduled to be completed in 2008, the Shanghai World Financial Center is a mixed used skyscraper; consisting of office space, hotel rooms and shopping zones at ground level. It will surpass Jin Mao Tower and will be the tallest skyscraper in Shanghai and in main land China.

Plans for a Template:Unit m. skyscraper in Boston have been confirmed^[8], to be called Trans National Place. Construction is tentatively scheduled to begin in 2008 and be completed in 2011. If completed, it would be the tallest building in Boston and New England.

Construction has started for a Template:Unit m skyscraper in Chicago to be completed in 2011, the Chicago Spire with 150 floors is a mixed use skyscraper, also tallest residential building. Designed by Santiago Calatrava, it will be North America's tallest free-standing structure.

Quotations

"A chair is a very difficult object. A skyscraper is almost easier. That is why Chippendale is famous."

—Ludwig Mies van der Rohe

"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)

"A skyscraper is a boast in glass and steel."

—Mason Cooley

"The skyscraper establishes the block, the block creates the street, the street offers itself to man."

—Roland Barthes

"Manhattan has no choice but the skyward extrusion of the Grid itself; only the Skyscraper offers business the wide-open spaces of a man-made Wild West, a frontier in the sky."

—Rem Koolhaas

"As the twentieth century fades, North America is ceding skyscraper supremacy to Asia."

—Emily Mitchell in Time Magazine, (1994)

"The tall building ought to participate in the city as both a facade, connecting the walls of the street, and as an object against the sky."

—William Pedersen in Process Architecture, 1986

"Architecture is the alphabet of giants; it is the largest set of symbols ever made to meet the eyes of men. A tower stands up like a sort of simplified statue, of much more than heroic size."

—Gilbert Keith Chesterton