How does a sky lobby work?

For the supertall skyscrapers of today, elevator supply is one of the biggest issues. After all, with certain buildings climbing up over 100 floors, elevators that stop at each floor will take up unnecessary space and make getting around impossible.

This was the case with Chicago’s John Hancock Center, when architects got to work designing the 100 floor structure in the 1960s.

The solution? A unique elevator system that essentially emulates motorways.

Understanding the sky lobby

Imagine you have to get to the other side of a city. You likely wouldn’t travel through regular streets, stopping at every intersection and roundabout – you’d take the motorway, a high-speed thoroughfare designed to get you as close to your destination as possible. Once in the area, you’d hop off the motorway and use regular streets to navigate to your destination.

Sky lobbies are basically the same thing, applied to skyscrapers.

Supertall buildings will have anywhere from 1-4 sky lobbies spaced throughout the building. Large express elevators run between the ground floor and a specific sky lobby, bypassing all other floors. Once passengers arrive at the sky lobby, they board a ‘local’ elevator which serves a specific set of floors around the sky lobby.

If you’re still a little confused, here’s an example. Imagine now you’re standing in the lobby of the Burj Khalifa – the tallest building in the world (for the moment). You need to get to the 55th floor, so you board one of three double deck shuttle elevators. This high speed elevator takes you up to the closest sky lobby, which in this case is on the 43rd floor, bypassing all other floors. Upon arrival, you board an elevator which takes you to your exact floor.

Without this system, you’d need to stay aboard an elevator as it climbs all 42 floors, stopping intermittently to disgorge passengers. It’s easy to see why this system is necessary.

The World Trade Center

Chicago’s famous John Hancock Center was the first building to introduce the sky lobby system in 1968 – but another, even more famous construction project would soon follow.

Architect Minoru Yamasaki knew that the gargantuan World Trade Center towers would be nearly impossible to navigate using a standard approach to elevators. Along with his team of engineers, he turned to the sky lobby system to solve the problem.

Interestingly, this team drew inspiration from the New York City Subway system, which used a similar approach with train cars. In the end, the World Trade Center towers each had 95 express elevators and local elevators, with two sky lobbies.

Looking ahead

With the world now firmly in the age of the supertall tower, sky lobbies will almost certainly become the norm. Of course, there’s a good chance that even more creative approaches will be necessary as towers climb ever higher.

See the latest projects and developments in the commercial sector, read relevant market reports and get in touch with the experts in the Commercial Design section.

Story by: David Renwick