Skyscraper

A skyscraper is a tall building with many habitable floors. Most modern sources define skyscrapers as being at least 100 metres (330 ft) or 150 metres (490 ft) in height, though there is no universally accepted definition, other than being very tall high-rise buildings. Skyscrapers may host offices, hotels, residential spaces, and retail spaces. Skyscrapers are a common feature of large cities, often due to a high demand for space and limited availability of land.

One common feature of skyscrapers is having a steel frame that supports curtain walls. These curtain walls either bear on the framework below or are suspended from the framework above, rather than resting on load-bearing walls of conventional construction. Some early skyscrapers have a steel frame that enables the construction of load-bearing walls taller than those made of reinforced concrete. Modern skyscraper walls are not load-bearing, and most skyscrapers are characterized by large surface areas of windows made possible by steel frames and curtain walls. However, skyscrapers can have curtain walls that mimic conventional walls with a small surface area of windows. Modern skyscrapers often have a tubular structure, and are designed to act like a hollow cylinder to resist wind, seismic, and other lateral loads. To appear more slender, allow less wind exposure and transmit more daylight to the ground, many skyscrapers have a design with setbacks, which in some cases is also structurally required.

Skyscrapers first appeared in the United States at the end of the 19th century, especially in the cities of New York City and Chicago. Following a building boom across the western world in the early 20th century, skyscraper development was halted in the 1930s by the Great Depression, and did not resume until the 1950s. A skyscraper boom in the downtowns of many American cities took place during the 1960s to 1980s. Towards the second half of the 20th century, skyscrapers began to be built more frequently outside the United States, particularly in East Asia and Southeast Asia during the 1990s. China has since overtaken the United States as the country with the most skyscrapers. Skyscrapers are an increasingly global phenomenon, and can be found in over 70 countries.

There are over 7 thousand skyscrapers over 150 m (492 ft) in height worldwide, most of which were built in the 21st century. Over three-quarters of skyscrapers taller than 150 m (492 ft) are located in Asia. Eighteen cities in the world have more than 100 skyscrapers that are taller than 150 m (492 ft), most recently Toronto and Singapore in 2025. The city with the most skyscrapers in the world is Hong Kong, with 569 skyscrapers, followed by Shenzhen in China with 444, New York City with 317, and Dubai in the United Arab Emirates with 270. Dubai is home to the tallest skyscraper in the world, the Burj Khalifa.

The term "skyscraper" was first applied to buildings of steel-framed construction of at least 10 stories in the late 19th century, a result of public amazement at the tall buildings being built in major American cities like New York City, Philadelphia, Boston, Chicago, Detroit, and St. Louis.

The first steel-frame skyscraper was the Home Insurance Building, originally 10 stories with a height of 42 m or 138 ft, in Chicago in 1885; two additional stories were added. Some point to Philadelphia's 10-story Jayne Building (1849–50) as a proto-skyscraper, or to New York's seven-floor Equitable Life Building, built in 1870. Steel skeleton construction has allowed for today's supertall skyscrapers now being built worldwide. The nomination of one structure versus another being the first skyscraper, and why, depends on what factors are stressed.

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.

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.