Rowan Williams Davies & Irwin Inc., Canada
The strength of CTBUH is that it brings together people of many different backgrounds, all of whom have an interest in tall buildings and the urban habitat. In the last CTBUH newsletter, Bill Baker described the enormous migration of people in countries such as China and India from the country to the city, a migration that dwarfs any other in human history. This brings both problems and opportunities. Unplanned growth in urban agglomerations can lead to the growth of slums with corresponding low quality of life, but well planned growth can lead to an enhanced quality of life as well as highly sustainable developments.
To achieve the goal of high quality, sustainable development requires a multi-disciplinary holistic approach, which brings us back to CTBUH and the broad and varied backgrounds of its members. What better forum could there be for promulgating the latest ideas in technology, planning, design, financing and development of new urban habitats. Therefore, make sure you bring your best ideas to the CTBUH program of conferences and publications.
There are many exciting possibilities to develop tall sustainable buildings. In many cases that I have seen the design is initially developed as a building like any other and then the question is asked: What features can we add to make it sustainable? This approach could be called the evolutionary method in which the “fittest” changes are the ones that are found to be the most effective in practice and that will survive in future designs. However, I personally would like to see the problem also being tackled from the opposite end in a more game changing manner: i.e. first coming up with methods for passive energy generation, be it solar, wind or geothermal, and then thinking about how a functional and aesthetically pleasing building form can be built around these ideas. A variety of interesting building forms can emerge from this, as we have seen in examples such as: the Pearl River Tower in Guangzhou, China; Manitoba Hydro Place in Winnipeg, Canada; and the Bahrain World Trade Center.
As a wind engineering consultant I get to rub shoulders with many very talented structural designers. The combination of these talents with modern software and computing systems has made possible feats of engineering design and construction that a century ago would have seemed like science fiction. And yet the design criteria used are still based largely on experience with much smaller structures and building codes written for these smaller structures. Therefore this is a fertile area for future research. CTBUH can help promote research in the needed areas and build consensus on design criteria. As just one example, should we allow some deflection beyond the elastic range under the dynamic actions of wind at ultimate load conditions, as is done in earthquake design? Current designs stay within the elastic range right up to ultimate wind loads. The potential savings of material, reductions in carbon footprint, and cost differences could be significant. Another example relates to the building’s serviceability. The design of a large number of tall buildings is governed by the need to limit motions, so as to stay within certain comfort criteria for the occupants. Yet there is still considerable discussion of what the criteria should be. We need to work towards better consensus and a useful approach is to make more use of existing motion simulators both for systematic research and for application to particular projects. We also need to take note of real experience in the existing stock of tall buildings and the design assumptions used.
As we emerge from the recession of the last two years the levels of activity in designing new urban centers and tall buildings are picking up again, which is good news for everyone! Let us look forward to the opportunity to bring energy and fresh thinking to the tasks of providing humankind with high quality, exciting and sustainable buildings and urban spaces.