Council on Tall Buildings and Urban Habitat
Conference Report

View this report in PDF as it appears in the CTBUH Journal, 2010 Issue I.

The 2009 Chicago conference was one of the best conferences in the Council’s 40-year history, despite the ravages of a worldwide economic downturn. 615 delegates, representing 278 companies from 35 countries, joined us on the Illinois Institute of Technology campus for the two day event, which featured 35 speakers, six tall building technical tours, an associated exhibition, a technical poster exhibit, a Welcome Reception at the Trump International Hotel & Tower, and the CTBUH 8th Annual Awards Dinner in Mies van der Rohe’s famous Crown Hall.


The over-riding theme of the conference,  Evolution of the Skyscraper: New challenges in a world of global warming and recession, was clearly tapping into the pressing issues of the day. Tall buildings have enjoyed almost two decades of unprecedented development—built in greater number, height and geographical spread than at any time in history. That position is now under threat from the twin challenges of global climate change and a severe international economic recession, and the conference convened delegates from around the world to debate the implications. Many projects have been cancelled, put on hold or are reducing their pace of moving forward as the recession tightens, and questions are increasingly being asked of the sustainable credentials of the high-rise building, especially in light of some of the design excesses of the past decade.

The Chicago conference occupied the unique juncture in time where we now stand; the global recession gives us an opportunity to pause and reflect on what tall buildings have become, and where they should head into the future. Are they meeting the challenges of climate change in helping create more sustainable urban environments? Is it appropriate for a tall building to be used as an icon to project the vitality of a city or country on a competitive world business stage? Have the fundamentals of skyscraper conception, financing, design and construction been sound in the past ten years of economic boom, or is there a need for reflection and change? What will be the signs of recovery and what policies can cities and governments implement to aid recovery? These are the questions that the conference addressed.


On Wednesday, October 21st, just prior to the conference, delegates had the opportunity to tour one of several buildings recently added additions to the Chicago skyline, through the pre-conference technical tours. Professionals involved in designing, developing and constructing The Trump International Hotel & Tower, Aqua Tower, Blue Cross Blue Shield Headquarters, Legacy at Millennium Park and One Museum Park West, guided delegates through their topped out or nearly completed skyscrapers.  The Chicago classic John Hancock Center was also part of the technical tours program. During that evening, the conference Welcome Reception was held in the luxurious ballroom on the 16th floor of the Trump International Hotel & Tower Chicago where, amongst other things, CTBUH presented a plaque to Eric Trump of the Trump Organization recognizing the Trump International Hotel & Tower Chicago as tallest building in the world with an all-concrete structure, the tallest mixed-use building in North America, the 2nd tallest building in North America, the 6th tallest building in the world and the tallest building built in the US in the past 35 years, since Willis Tower.

Chicago skyline seen from Millennium Park

New Icons
Two supertall towers that embody the latest iconic generation of tall buildings were specially featured at the conference: the Trump International Hotel & Tower Chicago and the Burj Dubai. Eric Trump and Andy Weiss (Trump Organization) showed that phased occupancy can contribute significantly to the financial feasibility of supertall buildings. Trump also mentioned that if you are going to do something the size of a supertall building, you must be prepared for the publicity, something which is also very much true for the Burj Dubai. Mohamed Ali Alabbar’s (Emaar Properties) presentation of the Dubai Tower showed that the 800+ meter tall tower embodies the development of Dubai as a whole on a global level. It also showed that supertall buildings and the direct urban environment of these towers are two entangled developments which enforce each other’s presence. 

Future Icons
Tony Kettle (RMJM) and Arthur Gensler (Gensler) presented supertall projects that are currently under construction or development: Gazprom Tower in St Petersburg and the Shanghai Tower. Kettle also commented on the debate about designing a supertall building in a city whose historic center has been recognized as a world heritage site by UNESCO. He argued that the location of the tower, a brownfield regeneration site, isn’t a threat to the character of the preservation area, and that in a city with an iconic history, there should be room for an iconic future as well. The building will be an icon for our 21st Century of Energy, just like the 18th, 19th and 20th centuries were dominated by the context of religion, trade and communism respectively. Gensler talked about designing a building as part of a trio of supertall buildings. In this context, the Jin Mao Building (1999) was designed to honor China's past and the World Financial Center (2008) as a tribute to the present. The naturally shaped Shanghai Tower reflects the future of China. The 120 degree twist is stretched over 140 floors.

Aspired Icons

How high can a tower go? Is one kilometer realistic? Nakheel Tower Dubai is a futuristic example. Towers at these heights can be constructed and have the potential to be financially successful. New equipment and partial occupancy construction techniques will need to be developed. Any tower over two kilometers will probably need pressurization to deal with our inner ear pressure. Many other issues related to accessibility and circulation, will also need to be addressed. The sustainability of these super-tall towers is also being questioned. Projects have been cancelled, put on hold or are reducing their pace of moving forward due to the economic crisis of the recent past.

Richard Tomasetti (Thornton Tomasetti) and Mark Mitcheson-Low (Woods Bagot) presented on the Chicago Spire and the Nakheel Tower in Dubai, respectively, offering their specific design solutions to problems that arise when building at extreme height, such as wind issues. Mitcheson-Low explained that the Nakheel Tower is not one solid tower but actually designed as stacked groups of four towers, which allow the wind to flow through the spaces in between these towers. Also some of the tall, but yet to be seen, developments were introduced, such as the American Commerce Center in Philadelphia presented by Garrett Miller (Hill International Real Estate partners) and Eric Kuhne’s (Eric Kuhne Associates) spectacular display of the Burj Mubarak al Kabir in Kuwait and other large scale projects. Although it’s tempting to focus on the supertall aspects, Kuhne described how his projects connect to the society in which they are placed. Contextuality and the connection of the ground plane to the neighborhood are very important elements in today’s designs. To qualify as an asset, it must be created to fit into its neighborhood.

Mohammed Ali Alabbar, Emaar

Eric Trump, Trump Organization

Adrian Smith, Adrian Smith + Gordon Gill Architecture

In the course of the 20th century, the iconic effects of skylines and skyscrapers gradually became another main cause for tall buildings, overtaking the need for density, especially when it comes to supertall buildings. Density became visibility, which is now being used to mimic density. Tallness (and hence visibility) can embody various messages, from an individual expression to values representing a society as a whole or the time of development. A very current theme is the topic of sustainability. Many new developments are now underway trying to make towers more durable and sensible through green technologies, smart and ecological design, green policies and certification programs. Speakers who presented individual projects eagerly pointed out the sustainable features.

On the first day, Steve Watts (Davis Langdon) introduced the topic by showing that next to economic maximization, ecological and social optimizations are also an important part of the triple bottom line of sustainability. Watts also suggested that nanotechnology might become the next big development in the structural design of tall buildings. Dan Probst (Jones Lang LaSalle) noted a growing awareness of the importance of sustainable building performance amongst office clients. Representative green buildings matter, especially to the financial industry. It is up to the suppliers of office space that an investment in sustainable features can be cost effective and beneficial to the working environment, especially in the long run. 

Mun Summ Wong (WOHA) and Russell Gilchrist (SOM) presented projects where sustainability has a profound impact on the appearance of the tower. Wong showed the Newton Suites Tower in Singapore, a green tower which uses wind to naturally ventilate the building and employs a full height  green wall. Gilchrist talked about the Pearl River Tower in Guangzhou, which has been designed to optimize the capturing of wind for energy production through turbines. Adrian Smith (Adrian Smith + Gordon Gill Architecture) presented the plans for a green retrofit of the Willis (Sears) Tower in Chicago and the results of a study on how the Chicago Loop could be  "decarbonized." Russ Huffer (Viracon) and Guy Turner (Intelligent Engineering / SPS Floors) talked about sustainability at the product level through glazing and floors.

…and Urban Habitat

Another theme that received a good amount of attention was that of the urban habitat. Through comparing East and West coast cities in the United States, Clark Manus (Heller Manus Architects / AIA) recommended more attention to the urban space between the tall buildings and the livability of city centers and communities. Development should be focused on more than obtaining LEED certification alone. Sustainability is more than the sum of the proper ingredients, it’s also about how these are mixed synergistically that really adds value.  To grasp the qualities of the combination of urban density and tall buildings, Carol Willis (Skyscraper Museum) compared several examples of density by displaying cities which are generally considered to be dense. By doing so, she showed that density comes in many shapes and forms. In order to distinguish the urban density and the life styles that come with it as seen in Manhattan, she introduced the term of “Vertical Density”.

The topic was further discussed in a panel which included Sandy Diehl (United Technologies), Richard Hanson (Mesa Development), Carol Willis (Skyscraper Museum) and Adrian Smith (Adrian Smith + Gordon Gill Architecture), which was moderated by Janice Tuchman (ENR/McGraw-Hill). The panel debated the sustainable merits of dense living, compared to low-rise and out-of-town living. The importance of livable city centers was also the focus of the presentation by John Portman, the Lynn Beedle Lifetime Achievement Award winner. He reflected on his impressive career, which spans almost five decades.

Richard J. Daley, City of Chicago


Happy Anniversary!
As part of the celebrations of the 40th Anniversary of the Council, one session brought six past chairmen onto the stage. Leslie Robertso (1985–1990), Charles DeBenedittis (1990–1993), Gilberto do Valle (1993–1996), Shankar Nair (1996–2001), Ron Klemencic (2001–2006) and David Scott (2006–2009) were asked to reflect on the time that they had lead the Council. These memories showed once again that the founder and long time chairman and director Lynn Beedle really embodied all that represented the Council on Tall Buildings.

Prior to his induction as the new chairman at the awards dinner on the Thursday evening, Chairman Elect Sang Dae Kim was asked to say a few words by outgoing Chairman David Scott. Kim told us that he hopes to make the Council as strong in Asia and South East Asia as it is in the US. His main areas of focus will be threefold:  the Council's finances, bringing in more academic people, and bringing in more experts.

On Friday, the final Conference presentation looked forward to next year, as the Mumbai Metropolitan Region Development Authority described the current state of urbanization in Mumbai. This was an excellent introduction for us as we are anticipating our Mumbai World Conference in February 2010.

Professor Sang Dae Kim, newly installed Chairman of the CTBUH, closed the Conference with final words and an invitation to attend the Mumbai World Conference. As the CTBUH changes leadership and looks to the future of Tall Buildings, the questions of urban design will become more focused as we approach our next gathering in Mumbai.

What this all added up to over the two days was a number of clear messages: that tall buildings have recently enjoyed a period of somewhat frenzied development unprecedented in the 125-year history of the typology; that this boom period had led to, in some cases, excess and buildings/designs that are inappropriate on cultural, economic and environmental grounds; that the current economic environment is more difficult for the support of tall buildings than any in recent history; that the development of tall buildings would unquestionably be affected in the short- to mid-term, resulting in a likely dearth of tall buildings being completed in a few years time; that this period of current relative inactivity gives us an opportunity to refocus the typology along more appropriate and sustainable lines; and that tall buildings are here to stay for the long term.

In the 40th anniversary year of the Council on Tall Buildings and Urban Habitat, it was perhaps this last message that was most reassuring. Unlike numerous periods in history where varying factors (lack of available technology, economic recessions, terrorist attacks) have led to premature announcements of the death of tall buildings, this conference made clear that the potential benefits of the typology have now tipped the balance firmly in favor of them in the long run. These benefits include: the contribution to increased urban density/vitality and more sustainable patterns of life; the potential for energy-generation; the positive branding of cities on a competitive international scale; and the traditional drivers of return on investment and projection of a corporate brand.

The conference thus concluded that, despite the temporary hiatus caused by the current recession, tall buildings will remain a vital part of the urban fabric of many cities the world over moving forward. Equally clear from the conference however, is the fact that the typology needs to first evolve into something better to meet the considerable challenges of the day, especially on environmental grounds. 

(Image of the Chicago skyline © Jan Klerks/CTBUH. All other images © CTBUH, photographer: Steve Becker/