Recording tall tales: the Council on Tall Buildings and Urban Habitat

People love to look up and marvel at tall buildings, and some like to peer down from up high. There’s just something fascinating about skyscrapers, and one organization has its eyes on them even more than tourists do.

The Council on Tall Buildings and Urban Habitat (CTBUH) regularly publishes statistics and reports on the world’s tallest skyscrapers. The organization’s data on high-rises is an important resource for the designers and builders that make vertical urbanization possible.

Daniel Safarik, CTBUH Journal Editor and newly appointed China Office Director at CTBUH, introduces his organization and provides insight into the history, status quo and future of tall buildings, as well as their role in urbanization.

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Published on 23.02.2015

The roots of the CTBUH

The Council on Tall Buildings and Urban Habitat was founded in 1969 in the unlikely location of Bethlehem, Pennsylvania. Structural Engineering professor Lynn S. Beedle at Lehigh University saw that important research was going on within academia, and at the same time observed a trend towards increasingly tall buildings, with the construction of the World Trade Center, Sears Tower and the John Hancock Center, all which employed new and different techniques in steel construction.

Beedle recognized the importance of creating a platform for structural engineers and academics to build up a general body of knowledge. Now, all kinds of tall building stakeholders take part in the CTBUH from around the world to promote a holistic and interdisciplinary approach to the study of tall buildings and urban habitats.

Today, the Council aims to continue building upon its body of information on tall buildings, and explore their relationship with the urban environment. The CTBUH thereby serves as an essential resource for all building stakeholders.

Meet the editor

Daniel Safarik is the CTBUH Journal Editor. He grew up near Chicago where he encountered many tall buildings, including the Willis Tower – formerly the Sears Tower and world’s tallest building from 1973 to 1998. In fact, Safarik’s grandfather worked as an electrician in the Sears Tower while it was under construction. As a child, he was deeply impressed by a picture of his grandfather standing on the 101st floor with nothing but air behind him and the city some 400 meters below.

Daniel Safarik’s unique background in journalism and architecture makes him perfectly suited to life at CTBUH. His work in the organization involves penning and editing press releases, books and research reports, as well as technical publications and general statistics. As if writing about architecture all day weren’t enough, he also authors his own blog called Unfrozen.

When asked about his favorite building of all time, Safarik showed both his romantic and practical side: “The Chrysler Building will always win the beauty contest – nothing expresses the roaring twenties and American ingenuity like that building.” The Chicago native, however, could not forget his roots: “The John Hancock Center and Sears Tower in Chicago were the most influential in my personal development.”

The developments tall buildings stand on

The skyscrapers of today owe their height to their history. Drawing on the example of multi-use buildings, Safarik explains how current developments have been made possible by innovations from the past.

“The increasing number of mixed-used buildings owe their existence and potential for beauty to two architectural developments more than any other: outriggers and megaframes.” This kind of building requires a structural system that not only keeps it stable, i.e. prevents over-swaying and discomfort during wind and seismic events, it must also be flexible enough to adapt to various needs that can change over time.

Outriggers are a key component to achieving this flexibility. Skyscrapers must have a highly stable and strong core. Outriggers – rigid frameworks that extend out from the core – are built out in cantilevered fashion approximately every 10 or 20 floors, providing extra lateral stability. The floors of the building in some cases “hang” from the outrigger above them, allowing for unobstructed interiors that do not require rigid structural elements like pillars.

Schematic drawing of building outrigger design (exemplarily shown for Shanghai Tower)

Megaframes, for their part, provide further stability from the outside, reinforcing a structure’s façade. They act as a building’s exoskeleton and are especially important for poetic, twisting and curving exterior shapes. Outriggers and megaframes are just two of many developments that have made some of the most flexible and beautiful buildings a reality.

“It’s more likely that we’ll see more horizontal connections than to find 1-kilometer-tall buildings in every city.”

Daniel Safarik

Director, China Office, Editor, CTBUH Journal, Council on Tall Buildings and Urban Habitat

Predicting the future: cities in the sky?

For the future, one thing is certain: urban populations will get denser. What is not so sure, however, is how exactly cities will cope with this consolidation. Though sci-fi classics like Metropolis and Blade Runner have offered some intriguing visions of futuristic cities, it is probably more reliable to ask an expert in skyscrapers and urbanization such as Daniel Safarik.

According to Safarik, increased urbanization will probably not result in a large amount of spectacularly tall buildings, but more and more 20-50 story buildings – and people are going to need more connections at higher levels. In order to make living in the upper floors more attractive, developers will have to bring many of the things available at the ground level skyward.

This means that all the necessities and attractions available on the ground need to start moving up. More connections between buildings via skybridges will also help one building’s attractiveness to build upon that of its neighbors.


Changing demands on transportation

Both in terms of space utilization and energy consumption, the world’s population has already grown past the point where it is no longer possible for every family in the world to have a big yard with a white picket fence and a golden retriever. This means that humanity’s occupation of the vertical realm is not just a fad, it’s a necessity.

If we assume that we will also need more connections between buildings, this would surely result in a more integrated transportation environment. Safarik put it clearly and succinctly: “Vertical and horizontal transportation will need to converge.”

People’s demands on transportation will rise as more and more people come to live in cities, whether they want to travel from building to building, metro to mall, or home to office. The arrival of multi-carriage elevator systems, such as MULTI with its potential for horizontal travel, will be one important step in that direction.


Skyscrapers and the environment

Safarik also praises a current trend that balances the logistical need for vertical habitation with the basic human need for access to nature: green walls. The history of green walls goes back to the early 1990s in the work of ecologist/architect Ken Yeang, who showed how a building can support more greenery than the lot it is built on.

Green walls can be implemented as gardens located inside of buildings, making internal spaces more welcoming. Set for completion in mid-2015, the Shanghai Tower will offer several such sky gardens as open atria with restaurants, coffee shops and convenience stores.

In November 2014, CTBUH named One Central Park in Sydney “Best Tall Building Worldwide” for 2014. The complex puts its green walls outside the buildings, creating the overgrown vine look reminiscent of old college buildings. The greenery also plays a major role in the building’s shading strategy.

Smart Building "One Central Park" in Sydney

Skyscraper factfinder paradise

The CTBUH’s mission is “to disseminate multi-disciplinary information on tall buildings and sustainable urban environments, to maximize the international interaction of professionals involved in creating the built environment, and to make the latest knowledge available to professionals in a useful form.”

The information provided at the CTBUH’s Skyscraper Center website is even fascinating for non-building professionals. Plus, it is a much easier way of surveying tall buildings than the method Daniel Safarik admitted to using as a child: “As a kid I used to climb my town’s local landfill to catch a glimpse of the Chicago skyline.”

New York Chrysler Building:
Image 1: Photograph “New York Chrysler Building” by Flickr User Jacob Bøtter, CC BY 2.0

John Hancock Building:
Image 2: Photograph “John Hancock Building” by Flickr User Kyle Monahan, CC BY 2.0

Sears Tower:
Image 3: Photograph “Sears Tower” by Flickr User Allan Henderson, CC by ND 2.0

Sears Tower:
Image 4: Photograph “Sears Tower” by Flickr User Neal Jennings, CC BY-SA 2.0

Shanghai Tower:
Image 5: Photograph “Shanghai Tower” by Flickr User ronghualu, CC BY-ND 2.0

One Central Park Sydney:
Image 6: Photograph “One Central Park Sydney” by Flickr User Rob Deutscher, CC BY 2.0, Design architect: Ateliers Jean Nouvel. Collaborating architect: PTW Architects