With Jean Nouvel's Torre Agbar opening in Barcelona on 16 September 2005, high-rise buildings were the talk of the LEAF Awards. A particular high point was the LEAF panel discussion, 'High rise of the future', led by MAKE Architects' Ken Shuttleworth, one of the architects behind London's Swiss Re Tower.
Shuttleworth has a keen interest in environmental issues, especially CO2 reduction, and has pioneered the creation of more energy-efficient towers. 'After all,' he said, 'every city needs lungs'.
The presentation showcased some of MAKE's innovative designs for planned towers. Regarding the positioning of individual towers within an urban setting, Shuttleworth cited the example of the medieval Tuscan city of San Gimignano, known worldwide as 'la cittá dalle belle torri' ('the city with the beautiful towers'). He believed the same kind of cluster of high-rise buildings would continue to influence urban tower design in the future. Shuttleworth's prognosis is an increase in mixed-use projects and more innovative design.
In recent years, designers of high-rise buildings have become more interested in the views of and from their towers, calculating sun angles in relation to panel positioning and so on. This preoccupation came as no great surprise to Shuttleworth; the top and bottom areas of a tower are the most important elements of the building, he said, and the view out is one of its main assets, a fact reflected in the current trend towards making towers larger at the top.
ENGINEERING AND SUSTAINABILITY
Arup's David Glover went on to look at high-rise buildings from an engineering perspective, and predicted that new forms would shape the future of tower engineering, delivering greater complexity and new lifting techniques. 'High density is the way forward,' he proclaimed. Once again, ecology is a crucial component; mixed use, land reuse and use of existing infrastructure as nodes are all becoming increasingly important. Glover was unequivocal: 'Buildings nowadays need to be self-sustaining,'
In another bold statement, Glover told the assembled delegates: 'The centre core is dead', citing how decentralisation of building systems, waste management and better designed workspace is helping create a new generation of tall buildings.
Schmidlin's Richard Till drew attention to the role of 3D geometry and building physics, observing how facades that can adapt to hot summers and cold winters are becoming a necessity due to climate change and the growing need to cut power usage. These facades are light-responsive, and shading manipulation is already a common feature in many high-rise properties.
Lifting strategies are also becoming more important, according to Kone's Johannes de Jong. 'You can dramatically reduce energy consumption by improving the efficiency of machines,' he added. The future will see buildings broken down into different sections, with lifts operating in a zig-zag structure.
Interestingly, in terms of security, 9/11 has not affected the construction industry in the way it has other industries. Ken Shuttleworth went further: '9/11 has had no effect on design, except for the buildings to be constructed on the actual site. Architects have even worked on solutions to minimise the consequences of similar attacks, but there is no demand.' David Glover agreed, pointing out that even the traditional collapse issue does not appear on the agenda anymore.
Instead, topics such as building management are taking increasing priority for architects and their clients. Johannes de Jong observed how in modern high-rise buildings, lifts now function as an escape route, and that hopefully this would soon render obsolete the sign that reads 'do not use lift in case of fire'.
The issue of wind obviously remains crucial, especially in densely populated urban clusters. However, Shuttleworth explained that certain structures, such as the Swiss Re Tower in London, with its form minimising the wind draft, can actually improve wind conditions.
Regardless of shape, it looks certain that the stock of high-rise building design will continue to rise in the future.