With the collapse of the World Trade Centre, the interest in skyscrapers has been renewed. By definition, a skyscraper is any high building intended for office or commercial use. There are no figures or guidelines as to the height a skyscraper must be to be classified as such; the only thing of importance is, that is is higher than the rest of the surrounding buildings and therefore changes the skyline of the city considerably. Skyscrapers are a rather recent phenomenon which develops fast with the skill of builders and the advancement of technology.

Today, the materials for most skyscrapers are steel and concrete. Before that,. multi-storey buildings were originally constructed out of brick or stone, materials that are too heavy and impractical. When glass facades began to get popular, elevators had to be constructed to enable the workers to get to higher storeys.

The most notable examples of skyscrapers are the Empire State Building and the Flatiron building in New York, the Willis Tower in Chicago, the Petronas Twin Towers in Kuala Lumpur and the Burj Khalifa in Dubai. Chicago, New York and Hong Kong are reportedly the cities with the most impressive skylines. Historically speaking, skyscrapers came into being out of the industrialised age and therefore started out in the late 19th century in England and the USA. However there are a considerable number of tall buildings in Australia, Latin America and Asia today. In Europe, the first half of the 20th century saw a low rise in the building of skyscrapers due to aesthetical objections and issues in fire safety. Today, skyscrapers appear predominantly in areas where there is not much space, such as city centres.

Challenges for builders and architects of skyscrapers are predominantly factors concerning weather conditions, such as wind or earthquakes, as well as the problem of fire inside such a multi-storey building. Another more recent concern is sustainability: A skyscraper requires vast amounts of electricity and water, which is anything than environmentally friendly. Scientists and architects are working on modern ecological buildings to increase sustainability.