FEB 2019, Sebastian Desand

High-rise building or skyscraper: what’s the difference?

There are approximately half million buildings under 100 meters around the world today. Those are the structures driving outdoor comfort in the cities, making a significant impact in solar radiation and influencing wind speeds.

“Skyscraper” as a concept was used for the first time to define the 42-meter-high buildings constructed in Chicago, year 1885. Before that, all tall structures around the world were religious buildings. The highest being Ulm Minster, a church in Germany (161 m); and the oldest, the Great Pyramid of Giza, in Egypt (145 m).

Building tall structures for people to actually live in (not only came-and-go, as in religious institution) was a big shift for engineers and architects from the 20th Century. It increased the overall complexity of a construction endeavor: the tall buildings don’t only have to fight gravity and be aesthetically appealing, they also have to create comfortable and safe environment for people. Both inside the building and in the surroundings.

Since the American Industrial Revolution, significant advances happened in the construction industry, the structures got higher and the vocabulary had to adapt. Nowadays, there’s a general consensus that buildings with 40+ floors, 150-meter-high or greater are called “skyscrapers”.

For buildings above a height of 300 meter, the term "supertall" can be used, while the ones reaching beyond 600 m are classified as "megatall". The Council on Tall Buildings and Urban Habitat (CTBUH) is THE authority when it comes to those definitions.

“High-rise buildings” definition, though, can vary according to different references. it’s a general term for multi-story structures taller than 35 meters. It’s usually a development with more than 9 stories, which in the skyline of a dense city can seem to be a fairly small structure. But they are not.

In reality, structures taller than 35 meters already cause significant impact on the urban context. Not only visually and aesthetically, but also from an environmental perspective such as sun light exposure, wind comfort and pollution dispersion.

This is how a 36-meter-high structure looks like in a dense skyline.
This is how a 32-meter-high structure looks like in a not so populated city.

Although a lot of spotlight has been spread towards supertall structures (due to its obvious complexity and audacious efforts), the majority of new structure being built around the world are floating within the borders of 35 to 100 meter high. Today, there are approximately half million of those buildings around the world!

Those are the structures driving outdoor comfort in the cities, making a significant impact in solar radiation and influencing wind speeds. They are in practical terms defining the city for the inhabitants. But still, most requirements regarding the study of pedestrian comfort in the design phase is limited to buildings higher than 100 meters.

Why is this the case? Simply because wind simulations has been complex, time consuming, expensive and sometimes unreliable. This is not the case anymore.

New technology allows building designers and engineers to conduct fast and accurate wind simulations for buildings lower than 100 meters. Now we CAN truly design and build cities in harmony with the wind. What an exciting time we live in.

Skyscrapers are awesome, but what’s really changing cityscapes around the world are the buildings measuring between 35 and 100 m. The city of Seoul alone has more than 8,5K of them