Imagine the future: sustainable skyscrapers

Envisioning the urban skyscraper of 2050

A high-rise for a warming and overpopulated Earth.

Cable cars, algae bio-fuel cells, and urban agriculture are sandwiched into just a small slice of Arup's future skyscraper.
Cable cars, algae bio-fuel cells, and urban agriculture are sandwiched into just a small slice of Arup’s future skyscraper.
Rob Hunt/Arup

The urban buildings of the near-future will be tall, smart, adaptable, responsive, honest, modular, recyclable, clean, and deeply embedded into the systems of their host cities, if an imaginative vision from Arup’s Foresight team is anything to judge by. In its evocatively titled It’s Alive, Arup (the firm responsible for the structural design of the iconic Sydney Opera House) asks if we can imagine the urban building of the future while simultaneously presenting its take on the matter. The report contains plenty of ideas, albeit briefly stated, so I thought it would be fun to identify some of today’s science and technology that has made it into Arup’s skyscraper of tomorrow and discuss whether Arup’s vision is more grounded in fact or fiction.

It was the best of times, it was the worst of times

Arup’s future-scraper is the product of its time; a time 37 years from now that will suck and be awesome in approximately equal measures. Why suck? Because 37 years will see us through to the year 2050, and Arup shares (or perhaps borrows) the OECD’s troubling forecast of a warming, overpopulated Earth hungry for, yet deficient in, essential resources. According to this narrative, there will be 9 billion people, with 6.3 billion living in towns and cities.

The good news is that we’ll still have iPhones—or their future-proxies, at least. Arup describes the denizens of our future cities as “net-native adults” who have grown up with smart cities, smart clothes, and smart objects. The Internet of Things will be ubiquitous, Arup suggests; presumably to the point that it has been abbreviated simply to “things,” the “Internet of” having been long since forgotten.

The specific technology that Arup predicts will make up our buildings varies from the likely (or even current) to the speculative, the specific to the vague. Let’s start with the obvious.

The big picture: Tall and modular

The aesthetic merits of tall buildings can be debated, but if humanity is set to grow and become increasingly urbanized, cities either have to grow upward our outward. There are arguments that the former is the more environmentally sound approach, not least because urban sprawl is prevented, and existing infrastructure can be reused (or, if necessary, upgraded). Where green belt policy is in effect, building outward may not even be an option, which comes with consequences. In 2005, the Government of Ontario passed legislation to designate a green belt around Toronto and the Golden Horseshoe. As of September 2012, Toronto had 147 tall buildings under construction. Toronto is an extreme case by North American standards, but even so, Arup’s prediction that the buildings of the near-future will be tall appears sound, perhaps a no-brainer.

But modular skyscrapers? Rob Hunt’s illustration of Arup’s future-scraper is pleasingly reminiscent of the futuristic visions of the 1970s depicting inter-stellar space hulks and off-world colonies (c.f. Donald E. Davis’ painting of the interior of a Stanford torus). It shows a skyscraper composed of modular pods that can be replaced as the requirements of use change. “In this emerging age, with significant developments in construction—prefabricated and modular systems are moved and assembled by robots that work seamlessly together to install, detect, repair and upgrades components of the building system,” Arup writes. A new start-up fails? No problem. The building’s army of robotic workers can replace its office and all its prefabricated fixtures, with a new one tailored to the needs of the next (or instead with a pizzeria, tropical garden, or small suite of studio apartments).

Today, modular buildings are more likely to be kit houses, with components selected to meet the needs of the user. Modular buildings of any scale are few. Raines Court in London, built in 2003, is a residential block of 53 flats. Each was factory-built, complete with kitchens and bathrooms, plumbing and electrics. The first phase saw 29 units put together and connected in a mere five days. However, the developer has said that until such modules are mass-produced, modular construction is “no cheaper” than traditional construction methods, which puts us firmly into vicious circle territory. Nevertheless, a large modular residential building at 335 East 27th Street in Manhattan is on the cards. “My Micro NY,” the winner of Mayor Bloomberg’s adAPT NYC competition, will be assembled from 55 locally built “micro-units” of between 250 and 370 square feet.

Prefabrication of tall buildings is increasingly common, however. Notionally a step back from full modular building, prefabrication is allowing construction of large buildings in record time. In November, a ten-story residential block, Instacon, was built in two days in the Punjab. The rapid-building efforts of China’s Broad Group, who built a 15-story hotel in six days and a 30-story hotel in 15, are attracting inevitable attention, though these efforts would be eclipsed, at least as a spectacle, if its plans to build the world’s tallest skyscraper in 90 days are successful. These record times are massaged slightly: they tend not to include groundwork or time spent in the factory.

It seems likely that the urban buildings of 2050 will be prefabricated, but whether modular construction takes over is anyone’s guess. A modular future might well result in skyscrapers looking very much more alike. A more likely bet is that future skyscrapers will go up in the proverbial blink of an eye.

Which is to say nothing of the robots. The odd window-cleaning robot and quad-rotor automatons that can build rudimentary walls aside, we are still in the early days of robot construction workers, let alone automatons that can reconfigure skyscrapers on a whim. Research at Cornell has brought about a robotwhich can navigate a simple truss structure, adding and removing components as it goes. But if robots are to revolutionize construction, perhaps they will first do so in quiet, inconspicuous ways, such as laying out and marking ground more quickly and accurately. But who knows? Perhaps the International Association for Automation and Robotics in Construction (IAARC) will amaze us any day now.

Wired for… everything

Arup’s future-scraper, we’re told, will be deeply embedded into the infrastructure of the city. Nowhere is this more apparent than in transportation, with buildings themselves becoming transportation hubs. Trains arrive via futuristic underground tube systems, and… hang on. If you work in a building directly above a metro station you will understand the advantages of such proximity (even if you do have to walk outside for a few yards.) “Integration,” then, is really just a blurring of the boundaries between the station and building. It’s already happened, to varying degrees, at buildings like Canary Wharf and The Shard in London, Nagoya Station in Japan, the MetLife Building (above Grand Central Terminal) in New York, and the CitiGroup Center in Chicago.

Arup’s illustrations also depict underground parking and incoming pedestrian bridges at a high level. The former is not unusual (overlooking the fact that the cars also arrive by underground tube), and the latter is by no means unheard of. The skybridge connects the 41st and 42nd stories of the Petronas Towers in Kuala Lumpur. Perhaps more tantalizing to those of us that work in the upper stories of high-rise buildings is the prospect of arriving to work via gondola cable car, which Arup’s illustration shows coming into its skyscraper about half way up. And yet cities are increasingly looking to gondola lifts, if for sight-seers as much as commuters. A Guardian report last November listed Algiers, Barcelona, Bolzano, Koblenz, New York, Oporto, Portland, and Rio as cities with gondola cable cars. However, for a cable car integrated into a high-rise, you may have to travel to Singapore, judging by this YouTube video.

A bridge here and a cable car there may demonstrate that the technological capability of this part of Arup’s vision already exists, but Arup is imagining that by 2050 these systems could be much more widely adopted and deeply embedded in our cities. That may be, though one shouldn’t overlook the sterling work undertaken by the humble elevator, which surely isn’t going to disappear completely by 2050.

Of course this rich interconnectedness is not limited to transport. Buildings will have the obligatory connections to the smart grid, water, fuel, waste, and anything else that will be deliverable or discardable by subterranean tube and pipe by then.

More than a front

Things take a turn for the high tech when it comes to the building’s facades. “This exterior membrane provides opportunities for everything from integrated communication networks, to food and energy production,” Arup writes.

The document singles out photovoltaic paint as its solar technology of choice. Coincidentally, spray-on plastic photovoltaic cells were in the news only last week, though they’re far from a new idea. Why stop at paint, though? Photovoltaic glass (also in the news last week, also not such a new thing) could potentially be integrated into the windows. The amount of solar research happening is dizzying, with numerous developments reported every week. Predicting which will make it out of the lab and into the market is a daunting prospect, though the steady march of solar technology overall seems inexorable. Perhaps by 2050 the cost of solar paint, solar tiles, and solar windows will have fallen to the point that they’re commercially viable while allowing for the fact that all these skyscrapers will inevitably cast shadows on each other.

Arup also refers to “nanoparticle treatments applied to facade systems that have the capacity to neutralize airborne pollutants, capture CO2, and clean the air around each structure.” Again, it’s already possible to embed the photocatalyst titanium oxide into concrete, surface tiles or windows. When exposed to UV light, titanium dioxide can break down atmospheric pollutants. Where the words “self-cleaning” appear, titanium dioxide tends to follow.

And apparently these multifunctional facades will convert carbon dioxide into oxygen, presumably sequestering the carbon while they’re at it. Given that photosynthesis makes a fairly good fist of this already, a green wall might be a logical starting point. Hardly a new idea (effectively constituting about one seventh of the Wonders of the Ancient World), the practice of covering walls in plants is as popular today as it’s ever been. Yet Arup’s illustration describes this material as a membrane, showing no apparent plant life at all. Perhaps Arup is thinking more along the lines of Eco-cement, which absorbs CO2 as it sets. Preferable would be a material embedded with artificial photosynthesizers that continues to capture carbon through the life of the building. Suffice it to say that carbon capture, like solar power, is the subject of much research, and it’s far from ludicrous to assume that the buildings of the future will make more of an effort than they do today.

Arup also describes “heat recovery windows” that allow air in while capturing heat before it escapes. Such technology exists but could do with some slimming down. If our taste for wall-to-wall glazing is to continue (as Arup appears to think it will), then the thermal performance of glass will surely have to improve considerably in a resource-poor future.

When it comes to the building’s outer walls, Arup has drawn inspiration from a variety of current research and technology and imagined the implications for the future. Building facades is already the focus of progress in the construction industry, and it seems as safe a bet as any that this will continue.

Smart, clean, honest

Interaction between plant roots and soil produces a small amount of energy. The same principle could be used in algae biofuel cells.
Enlarge / Interaction between plant roots and soil produces a small amount of energy. The same principle could be used in algae biofuel cells.

Arup thinks that the skyscrapers of the future could routinely produce more energy and other resources than they consume. We’ve already mentioned photovoltaic paint, but Arup also envisages algae biofuel cells integrated into the building. Rather than simply farming algae and converting it into biofuel for combustion, the word “cells” implies a more nuanced process. In November, researchers at Wageningen University foundthey were able to generate 0.4W per square meter of marshland from microbial fuel cells (MFCs), which obtained energy from the interaction of plant roots and soil bacteria. In 2009, Penn State conducted research that found algae could “in principle, be used as a renewable source of electricity production in MFCs.”

The inclusion of wind turbines into the design would be predictable, were it not for the fact that these are to produce drinking water rather than energy. A company called Eole Water claims it can do just that. Arup also says that downdraft winds could be harnessed to generate power, so it arguably missed a trick in not making its future-scraper cylindrical, assuming the idea behind the Downdraft Tower has legs. Meanwhile, the presence of floors devoted to food production suggests, alas, that we’re not into Star Trek Replicator territory by then, though token farm floors many be less likely to come to pass.

Buildings that are claimed to produce as much or more energy than they occur with increasing frequency, but it’s one thing to claim this for a building and quite another to do and prove it. The idea that buildings could report their net resource consumption or production has been knocking about since at least 2007. The suggestion is still that outward-facing displays at ground level will show this real-time information to passers-by.

Honest Buildings is a website where a database of the world’s building’s is gradually being built. Among the information that can be added are the estimated energy consumption (baseline and peak), greenhouse gas emissions, etc. Much more in the spirit of Arup’s vision, though, is support for the Lucid Building Dashboard, an informational hub that can gather and report live information on a building’s consumption and output. Building managers need only to plug their dashboard ID into Honest Buildings, and suddenly the site becomes a hive of live energy reporting for buildings all over the world. Of course this will require building managers to actually do that, which, until such a time as everyone is itching to show off about how much energy their buildings don’t consume, may require some form of legislative stick. This would remove the need to actually walk past the building to check out its energy consumption.

Needless to say that the buildings of the future will have sensors up to (and including) its eyeballs, allowing it to intelligently match or adapt lighting, temperature and what have you for efficiency and/or comfort. Arup is on safe ground here, one feels.

Where do I park my jet pack?

Arup has clearly looked to the innovations of today in order to produce a vision of the urban building of 2050. But it’s no less imaginative, and all the more plausible, for having done so. The mishmash of technologies that has gone into the vision will have been scraped from the memories and consciousness of the Foresight Design Team, just as the examples I’ve called upon have been scraped from mine (and Google, obviously). Doubtless other things will have occurred to you.

And really, that’s about it… give or take some graphene.

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