# What is it like to build a skyscraper

## How high can a skyscraper get?

However, the Chalifa Tower may lose this title as the tallest building in the world as early as next year. Because then the Jeddah Tower (Jeddah Tower) should be finished in the city of Jeddah in Saudi Arabia and with a height of 1,007 meters would be the largest building in the world.

Originally it was even planned to build the Jeddah Tower 1,600 meters high. It turned out, however, that the ground at this point could not have supported such a large and therefore heavy building. Therefore it was decided to build the tower "only" around a thousand meters high.

If you want to know the maximum height you can build a building, basically just one question arises: How much building material can you stack on top of one another before the pressure of the upper floors on the lower floors becomes too great. Because whether brick, concrete or steel - every building material can only withstand a certain pressure before it deforms, breaks or tears. Skyscrapers like the Chalifa Tower are therefore built from high-strength steel and special concrete.

Scientists have tried to calculate the maximum height such a steel and concrete building can get before it collapses under its own weight.

They assumed that the building has a square or round floor plan and grows straight up. In doing so, they came to a maximum possible height of around 5,000 meters.

If you want to build even higher, the skyscraper has to get thinner and thinner towards the top. This reduces the weight of the upper floors and the skyscraper can become higher overall. The wider such a building is at the bottom, the more weight it can take here - and the more floors it can carry, with smaller areas at the top.

Scientists have calculated that a steel and concrete skyscraper in the shape of an Egyptian pyramid could even be up to 15 kilometers high using this method.

But not everything that is technically feasible also makes sense. Because if you build a thousand-meter high-rise, for example, then at this height only half of the total building area can be used, for example, for apartments, offices or shops.

The other half is occupied by building technology, supply areas, escape routes or the very large number of elevators that are required.

In the Chalifa tower, for example, entire floors, sometimes even several on top of each other, are reserved exclusively for the building's technology.

The higher you continue to build, the more the ratio of the usable area to the total building area decreases. In addition, the construction costs of each additional floor increase compared to those below.
As a result, a skyscraper becomes more and more uneconomical for its builder above a certain height. Because they have to recoup the construction and maintenance costs of the building by selling or renting the space.

It therefore makes little economic sense to build skyscrapers much higher than 1,500 meters.