My Skyscraper's Super Taller Than Yours: An Interview with the Council on Tall Buildings

The height of enormous buildings built of glass, concrete and steel isn’t something you might typically think of as fluid or subjective. Turns out, it’s both. A few weeks ago, the height of One World Trade Center changed overnight when the designers nixed a decorative enclosure around its 408-foot-tall needle, mainly because it would be impossible to maintain. Through a technicality, this will lower the building’s official height from 1,776 feet to 1,368. If this goes on record as the finished height of 1WTC, then Chicago’s Willis Tower, completed in 1973, will remain the tallest building in the U.S.

But as developers squabble over 1,400 feet versus 1,700 feet, China and the Middle East are pumping out supertall buildings at an incredible pace, leaving the U.S. – the historic home of my-tower’s-taller-than-yours competitions – in the steel dust. Willis Tower may be the tallest in the US at 1,451 feet, but it’s only the 35th tallest building in the world; the first is the Burj Khalifa (above), at 829.84 meters, which bests the next tallest building, Taipei 101, by 300 meters. In Japan, there’s talk of building a 730 meter pyramid that’s actually inspired by Blade Runner. Think about that for a second. I did, and then I asked Kevin Brass of the Council on Tall Buildings and Urban Habitat (CTBUH), the world-wide authority on tall buildings, what he thought about these height controversies, the chances of the U.S. getting supertall, and why we’ll always be comparing building size.

What exactly does the CTBUH do? What kind of authority do you have?

The CTBUH is a not-for-profit members organization supported by the world’s leading architects, engineers, designers and builders of tall buildings. We handle a wide variety of roles, including disseminating the latest technical knowledge and best practices through periodicals and books devoted to tall buildings, as well as regular events around the world. Right now the Council is focusing on the CTBUH World Congress in Shanghai. We publish our own research and technical guides, with the latest information on specific topics. The Council also maintains the world’s most detailed database on tall buildings, The Skyscraper Center, reflecting 40 years of research. And as you noted, we are also the arbiter of tallest building height designations around the world.

One World Trade Center recently became the tallest building in New York – again. What does that mean from your vantage point?

First off a quibble: We don’t consider a structure a building until it is completed and occupiable. People make a tower a living building. So until 1WTC is completed, we still list it simply as “under construction.” That said, 1WTC resonates on many symbolic and emotional levels that has nothing to do with architecture and engineering. It is a symbol of a city’s recovery and the resilience of a nation. Considering its location, the tower also represents the strength of the U.S. economy.

But even from a construction perspective 1WTC is an important building. There have only been three “tallest in the U.S.” buildings since the Empire State Building. Once the U.S. dominated tall building construction. As recently as 1970, 92 of the world’s 100 tallest buildings were in the U.S.; now only 26 are in the U.S. So 1WTC represents a major step for U.S. construction, illustrating that super tall buildings are still part of the urban planning for U.S. cities.

People very rarely experience the top of a building, except as part of a skyline. From the street, a building’s height over, say ten stories, has little effect on them. There’s been a lot of talk about the importance of density at a time when most of the world is living in cities, but why are people still obsessed with building super tall buildings?

People have always been fascinated by tall buildings, which bring elements of science fiction to the reality of a modern city. People are now living and working in the clouds. The act of standing on the street and looking to the sky at these incredible buildings is a powerful things, even for people accustomed to living in the city. In some ways, tall buildings rival the space program, in terms of capturing the public’s imagination. Both are reaching for the sky and using technology inconceivable a few years ago.

The controversy over measuring height is one that continues, as The Willis Tower (The Sears Tower) and 1WTC fight it out in the rankings. We tend to think the heights of buildings are fixed and objective, but there’s a surprising amount of controversy. Why is that, and where does CTBUH stand in the debate?

We take these discussions very seriously. Designations of “tallest” are very important to cities, countries and everyone involved with a building. It’s about more than bragging rights. These buildings are icons and play an important role in the identity and culture of a city, as well as serving as an attraction for business and tourism. We’ve developed a detailed formula for measuring buildings, taking into account very specific criteria. We’ve really set ourselves up as an impartial arbiter of these discussions. When we set a height, it is typically determined by reviewing the drawings or detailed discussions with the participants. We go to extraordinary lengths to make sure we accurately reflect the buildings’ true height. But still, there might be nuances in dispute, which is why we established a height committee to review any issues.

And, by the way, you are right about this being a long-standing issue. The most famous came in 1998, when Petronas Towers in Kuala Lumpur passed the then Sears Tower as the tallest in the world, only because the CTBUH did not include the antenna on top of Sears Tower. It was very controversial at the time, especially here in Chicago, the Council’s home base. But since then much of the controversy has died down and I think it’s fair to say the industry generally accepts the Council’s judgments. You can find the full criteria on our website.

What do you think the future of “the tallest building in the US” is? Do you see a chance for supertall building in this country?

Several factors are pushing tall building construction around the world. In many cities, horizontal development no longer makes sense. From a social, cultural and urban planning perspective growing vertically makes sense. There continues to be quite a bit of tall building construction, but there has not been very much super tall construction and little talk of a building taller than 1WTC. At a certain height, tall buildings stop making economic sense. Building beyond that height is more about ego and creating an icon for a city, which is why so many megatall buildings around the world are driven by attempts to create a national or civic identity, more than any economic equation. At the moment, U.S. developers are focusing on buildings that make economic sense. But it is inevitable that sooner or later a developer or a city will want to go higher than 1WTC.

Generally, where are you seeing the strongest impulse to build “supertall”?

In 2000, there were 263 buildings of more than 200 meters in the world. By the end of 2011 there were 775. In 2011, 88 buildings of more than 200 meters were finished, a record. Right now there is only one building over 600 meters; by 2020 we expect there to be nine. To answer your question, we are entering a new era of super tall construction, but it’s driven by Asia and Middle East, not the United States. The next world’s tallest will likely be Kingdom Tower, a kilometer-tall tower planned for Jeddah, Saudi Arabia. But China is leading the way. They have a need to reshape their cities and super-tall buildings are the most efficient way to efficiently address their civic needs. According to the United Nations, 50 percent of the world 7 billion people live in urban areas; by 2050 that will grow to 70 percent of 9 billion people in urban areas.

What are some of the technological innovations that are going to change how we build these towers?

There are a wide myriad of engineering and structural elements that make supertall buildings possible. But some of the biggest advances are a bit more mundane. Dramatic advancements in elevators make tall buildings possible. Without a quick and efficient way to get people from the bottom to the top, tall buildings won’t make sense. One of the biggest advances in the Burj Khalifa construction was figuring out how to pour concrete efficiently at 800 meters.

We recently celebrated the anniversary of the Empire State Building’s dedication. What sort of significance do you see historic tall buildings carrying in the future? The Empire State Building helped define a city. It was finished at the start of the Great Depression, yet stood as a symbol of the vitality of the United States and the economy. Tall buildings withstand the test of time, immune to the economic cycles and social tribulations of a city. In the modern age, tall buildings represent a new way for people to work and live, a sign of progress and a step toward creating the cities of the future that were once nothing more than dreams.

• Watching the World Sink and Explode From Atop its Tallest Building
• The Pleasure of Looking Down on Earth
• Tokyo’s Mega Skyscraper Pyramid