Council on Tall Buildings and Urban Habitat (CTBUH) executive director Antony Wood believes the answer lies in increasing the density of cities. Wood, who is also associate professor at the Illinois Institute of Technology in Chicago, says denser cities with concentrated land use and infrastructure offer more sustainable patterns of life. To achieve denser cities, the solution is to bring the city up to the sky.
Writing in the Asia edition of Modus, a publication by the Royal Institution of Chartered Surveyors, he says tall buildings have an important role to play in the viability of our ever-growing urban footprint on the planet. Such a role, though, calls for a new breed of skyscrapers because in their current form, most tall buildings are energy profligate – there’s higher energy consumption for operating and maintaining the buildings as well as higher embodied and operating energy needed to construct them.
Khel Tower, a vertical sporting facility proposed for Mumbai. A series of hotel towers lean past each other to allow views of the city and ocean, with suspended sporting facilities and fields in between (photo credit: CHBUH, IIT, Kent Hoffman & Mark Swingler
For tall buildings to serve as a sustainable solution to urban growth its typology needs to be reinvented, says Wood. Some of the considerations for the typology include variation in form, texture and scale; the inclusion of communal spaces; greening and landscaping; and the addition of skybridges.
“We need to bring all aspects of the city up to the sky. If cities are looking to concentrate perhaps 10 or 100 times more people on the same land through building tall, they need to replicate the facilities that exist at the ground up in the sky, including the parks and the pavements, the schools, and other public and civic functions,” he adds.
TATA Tower, an urban parking development proposed for India’s largest car company that also taps on renewable energy to power itself, its vehicles, and neighbouring towers (photo credit: CHBUH, IIT, Seth Ellsworth & Jayoung Kim)
Dr Kenneth Yeang of TR Hamzah & Yeang Sdn Bhd says, in reinventing the tall building type, structures must be designed as “vertical urbanism”, and tall building design must be regarded as “vertical urban design”.
“We need to view all those aspects of urban design that are conventionally crucial horizontally, and transpose these vertically, as urbanity in the sky. For example, a consideration in urban design is place-making. Vertical urbanism requires us to ask, ‘what is place-making in the sky’?” says the award-winning architect who’s regarded as the pioneer of the bioclimatic skyscraper.
In cities or locations that are already dense, such as Hong Kong and Singapore, Yeang suggests looking at intensifying existing tall built forms by linking tall buildings horizontally at upper levels. He also proposes better use of the spaces between buildings, the use of spaces over existing roads and motorways, as well as improved urban design and physical planning.
The Skybox uniquely comprises individually-stacked “boxes” which are inspired in function and orientation by differing physical aspects of the city e.g. horizon views. Each “box” responds to the individual needs of the occupants and the surrounding urban context (photo credit: CTBUH, IIT, Prairna Gupta)
Moving from concept to reality, he tells Green Publishing Asia, is “not such a big deal”, adding that “it just requires a change in mindset in architects and planners to rethink the design of the tall building type, as opposed to designing them conventionally as repetitive homogenous trays stacked one on top of the other with singular built form uses instead of multiple uses.”
Yeang also believes that such tall buildings will not require new construction and engineering technologies, but simply a rethink of the way we use existent engineering and construction systems. “What is crucial is to use clean tech engineering systems that are carbon neutral, and construction systems that facilitate disassembly, reuse and recycling.”
Yatra Towers, a series of linked towers proposed for Mumbai which retains the sense of the community and industry of the low-rise area which is swept into the sky (photo credit: CTBUH, IIT, Irene Matteini & Nathaniel, Hollister)
Wood reckons that this new breed of tall buildings is a market issue, involving not only direct benefits such as lower energy costs in the long run, but also communicating a message. “There is already a lot of research into making buildings more energy friendly. The Commerzbank Tower in Frankfurt, Germany, is considered the first sustainable tall building in Europe. It was commissioned by a company that wanted to show that it took its social responsibility seriously. Being very visible in the urban landscape, a tall building can be a great way to express a trend, a vision or a message. For this reason, many new tall building projects seek energy certification, such as LEED in the US,” he tells Green Publishing Asia.
Proponents of tall buildings as a sustainable solution to urban growth say such buildings need not involve increased costs in construction, as landuse will be intensified. In implementing sustainable strategies, Wood says it will be up to the developer to convince tenants and users that the extra costs of implementing these strategies are actually investments because they pay off in the long run.
Chicago Gateway, a proposed set of connected towers which connect Lake Michigan with the high-level urban environment via a large, floating “green podium.” This takes advantage of hydroponic farms, and becomes a vertical interface in a city network of green roofs connected by skybridges (photo credit: CTBUH, IIT, Won Woo Park)
He adds that in a number of older tall buildings that have been given a green retrofit, the costs have a payback time of between three and five years. Such was the case with the Empire State Building in New York City. In addition, energy saving was estimated at 38%.
Nonetheless, proponents concede that making tall buildings part of the solution for sustainable urban growth is not without challenges.
“Tall buildings have always been drivers of innovation. To build taller, one often runs into new problems, which need creative thinking to overcome them,” says Wood. He adds that presently there are a number of tall building projects that are experimenting with implementing sustainable technological innovations. For instance, wind turbines are integrated in tall buildings like the Pearl River Tower in Guangzhou, the Bahrain World Trade Centre in Manama and the Strata SE1 tower in London.
“The net effects of these strategies can be proven in theory, but it takes time, tweaking and monitoring to develop these ideas into strategies that can be implemented on a broader scale. It takes a certain courage and willingness to invest in these strategies,” he adds.
And that willingness is there, says Yeang. “We are beginning to see this shift towards this approach to designing the tall building. The problem is not with convincing clients and developers per se, but getting planning approving authorities to permit such building typologies.”