The future of skyscrapers: a mile high, slimmer than ever and made from wood

History does not want for dizzying fantasies of tall buildings.

From the Tower of Babel onwards, humanity has dreamed of ever-more wondrous skyscrapers, whether we knew them by that name or not. In 1851 an architect called Charles Burton proposed that the glass and iron left over from the Great Exhibition be used to construct a tower 1,000 feet (305 metres) tall – just short of the height of the Shard.

Burton promised, as so many architects have since, that “there was never so favourable an opportunity of erecting so gigantic a tower at so comparatively trifling a cost.” His tower, complete with a vertical steam train in place of the as-yet-not-invented passenger lift, was never built, and nor were so many other hyper-ambitious structures designed between Burton’s time and ours. 

That category includes Frank Lloyd Wright’s Mile High Illinois, which was proposed in 1956 and whose putative height was 50 per cent greater than that of the Burj Khalifa, our modern-day tallest building (828m/2,717ft). 

It also includes the X-Seed 4000, a monstrous 4km-high (2.5-mile) pyramid envisioned for Tokyo and up to a million of its inhabitants in 1995, and the Dynamic Tower, a 420-metre (1,378 ft) skyscraper offered to Dubai in 2008, each of whose floors might have rotated 360 degrees in 180 minutes (much like Brazil’s Suite Vollard, which is real and does rotate). 

This eerie graveyard of unborn skyscrapers could yet welcome the Tulip, a bulbous-topped neighbour to the Gherkin. Its construction was blocked by Sadiq Khan, the mayor of London, last year, although the building’s designers, the firm of the star British architect Norman Foster, have just begun their appeal.

So for each of the world’s 200-odd skyscrapers that are either supertall (300m/884 feet) or megatall (600m/1,969ft) there are many more that were never built. 

These unrealised and often unworkable envisionings of the future of skyscrapers have usually been grandiose, sometimes grotesque, and always ambitious. But they are not half as strange or wonderful as the skyscrapers that might arise within our lifetimes.

2019 was a boom year for supertalls. Just before the turn of the year, the Council on Tall Buildings and Urban Habitat (CTBUH), a Chicago-based body that is generally considered the global authority on skyscraper height, released its annual report of global construction. The year 2019, it said, was “remarkable for the tall building industry, as it saw 26 supertall buildings completed… the most in any year.” Worldwide, we are constructing 15 times as many buildings of 200m (656ft) height or more as we did in any year of the 1980s. “The appetite for especially tall buildings remains high,” the report concluded.

That report was issued on December 12. Four days later, health officials in Wuhan, a city home to three of the world’s tallest skyscrapers, began investigating an outbreak of the viral pneumonia that we now know as Covid-19. As we all know, the virus spread across the world, prompting national lockdowns whose economic consequences we have barely begun to suffer. Its many victims have included the travel sector and traditional white-collar working practices. Given that their tenants are mostly hotels and offices, this is bad news for skyscrapers.

“I’ve been in the commercial property market for 54 years,” says Tony Lorenz. “I’ve had four previous recessions” – he lists those of the mid-Seventies, early Eighties, early Nineties, and late Noughties –  “and the bottom line is that I’ve never seen anything like this at all.”

Lorenz, who runs a property consultancy of the same name in London, expects companies to cut their office space by around 20 per cent. Although social distancing rules will force employers to give workers more personal space than before, those workers have by now developed a taste, and an aptitude, for working from home. The headquarters of big banks, such as HSBC and Barclays, dominate the skyline of Canary Wharf, and those buildings have been all-but vacant since March. 

Many banks, prompted by pre-Covid factors such as Brexit, were already reducing their London office space, and some of their leaders, such as the Barclays chief executive Jes Staley, have publicly questioned whether they need a single, large headquarters at all. Where employers once took 21-year leases on offices, Lorenz says, they now ask for 10-year leases with five-year break clauses. Big building projects require big loans, but tenant skittishness, which the pandemic will only increase, is hardly conducive to confidence.

According to Lorenz, businesses that might previously have jointly occupied a large building now want smaller premises of their own. “There's a lot more demand for the self-contained building,” says Lorenz, “whereby tenants can actually run their own HR. 

"They can run their own security and mix only with people they know, instead of being sneezed over by some stranger in a completely different business.” 

A global economic slowdown; social distancing; a crackdown on high rise-building in China. These are not supportive conditions for further boom years. Large building projects take years, sometimes decades, which means that the CTBUH’s annual completion figures might not include a commensurate drop for another couple of years, but the 2020s look likely to be a leaner decade for skyscraper construction than the last.

None of this, however, amounts to an existential threat. Travel will return, and so will the office. “In the short run,” says Paul Cheshire, emeritus professor of economic geography at the LSE, “there will be substantial changes and major problems, but in the five-to-10 year horizon I think that things will revert to pretty much just as they were, with a few changes and more remote working.”

There is good evidence, he says, that the more densely an office area is populated, the more productive its work will be. In these “vertical agglomeration economies,” says Prof Cheshire, “it’s all a question of interactions between complementary skills and people. The problem with working remotely is that you don’t have accidental encounters.”

So the value of the sky-high office building will remain, and our reluctance to re-enter such buildings might vanish more quickly than we imagine. “You’ve got to remember,” says Herbert Wright, “that after 9/11, the biggest skyscraper disaster of the century so far, people said: ‘That’s the end of the skyscraper.’ And of course it wasn’t. It was actually the beginning of the biggest skyscraper boom ever, which is still going on around the world. Predictions of the end of the skyscraper have been made before and proved to be false.”

Wright, who is the author of London High, a guide to the capital’s skyscrapers, thinks that the crisis might even be helpful for British supertall construction. 

Buildings in London must not exceed 300m (984ft), a height exceeded by 15 skyscrapers in Manhattan alone. Within Canary Wharf, buildings must not exceed 235m (771ft), a limit imposed because of the proximity of planes flying in and out of London City Airport. Should the aviation industry suffer so badly that the airport shuts, Wright muses, “you’ll be able to go to 300 metres.”

There is no suggestion that London City Airport is under any more pressure than other airports, but the pandemic, as Wright suggests, might not be as deleterious for tall building construction as it seems. One way that this might happen is by decentralisation – Lorenz says that London-based companies, seeking to create several regional hubs rather than hive all their employees in one location, are now looking at office space in cities including Manchester, Birmingham and Cardiff. And there may be skyscraper-friendly changes within the capital, too. Building regulations, for so long the chief obstacle to skyscraper construction in Britain and elsewhere, have rarely looked so vulnerable.

A densely historic city like London is riddled with planning hazards. The best-known of these are the “protected vistas”, which are the views of landmark buildings such as St Paul’s Cathedral from raised points such as Primrose Hill in Camden and Blackheath Point in Greenwich. In total, there are 13 protected views. Plot them on a map and they look tripwires. 

Architects must ensure that their plans do not violate these sightlines, which have been protected since 1938. Sometimes this leads to architectural creativity, notably in the design of one of the City’s newer skyscrapers, 122 Leadenhall Street. Better known as “the Cheesegrater”, the building supposedly owes its distinctive wedge shape to its designers’ attempt to minimise their interference with the view of St Paul’s from the west.

These views are popular with day-trippers and beloved of conservationists, but critics say they hold back development and contribute to the housing crisis. “You can only see St Paul’s from Richmond Park three days a year because of the haze and the rain,” says Prof Cheshire.

London is not alone in governing its tall buildings in this way – San Francisco has protected views, and so do Portland, Vancouver and Edinburgh – and it is far from the most restrictive. European cities, which have centuries’-worth of elderly buildings to preserve, are far stricter than the great skyscraping cities of North America and Asia. Paris, for the sake of the Eiffel Tower, has a cap of 180m (590 feet) on new buildings – a limit that makes London look like Singapore.

Where the UK really differs is that, within those rules, building plans are approved or denied on a discretionary basis. This way of doing things, says Prof Cheshire, “is incredibly specific and unusual. And it’s primarily unusual because it’s discretionary.” Here, he says, “it’s always a political decision. It’s taken by the local planning authority, so it’s a political decision, and subject, therefore, to lobbying and all sorts of comings and goings.” Think of the Tulip – felled by the mayor rather than precluded by the rules.

The merit of this system is that appraising a potential skyline is a subjective matter. Some decisions, at least in theory, might be best made on a case-by-case basis. How could the architects of our planning laws have anticipated that their successors might have to deal with, in the Tulip, a tower compared to a sperm cell?

Then again, the rules-based French system, which has restrictions on design, finish and materials, might have quashed the plans immediately, without the years-long wrangling. This contrast makes discretionary planning, in the view of Prof Cheshire, “just an extraordinarily inefficient way of running a planning system.” 

Ambitious building projects in London take years to get started, as Cheshire explores in a recent paper with Dr Gerard Dericks, often require the services of glamorous and expensive trophy architects (e.g. Renzo Piano for the Shard and Norman Foster for the Gherkin) in order to woo politicians. Those politicians hear the sweet nothings of trophy architects in one ear and the chuntering of Nimbys in the other. “The shouts are usually loudest from those who feel that in some ways, a development is going to reduce the value of their house or make the city a worse place or something. The shouts are not from those who are going to benefit from it,” says Prof Cheshire.

The pandemic might shake things up. The Government’s campaign to “Build, Build, Build,” which seeks to jump-start the economy by encouraging construction, has relaxed rules around demolishing vacant buildings, adding storeys to pre-existing properties, and converting commercial buildings into housing. 

Further relaxations, perhaps of the discretionary planning system – “God, we can hope, can’t we?”, says Cheshire – could follow in Number 10’s planning policy paper, whose release is imminent, or in a White Paper later this year. It is unlikely that politicians will lay a finger on the Green Belt, the protected vistas, and the conservation areas. But a liberalising of the discretionary planning system could make it easier to build skyscrapers here – and perhaps easier to build more characterful skyscrapers.

That’s how we often think of London’s newer skyscrapers: characterful. The Cheesegrater, the Gherkin, the Walkie-Talkie, and the Can of Ham are to some eyes carbuncular, but at the very least are more arresting than the cuboids of Canary Wharf. In this way London is part of a broader trend towards a spectacular diversification of skyscraper design – a trend that is well under way and which promises novel construction styles and eloquent displays of national pride.

As well as cracking down on megatalls, China’s rulers have outlawed the popular practice of building large replicas of Western landmarks such as the US Capitol and the Eiffel Tower, as well as banning the weirdly-shaped experimental skyscrapers that Western architects have brought to their public bodies and big businesses. What looks likely to follow is an urban typology that is less chaotic and imitative and more authentically Chinese – and one that will still involve tall buildings.

Skyscrapers “have always been a way to put a place on a map,” says Judith Dupré, author of Skyscrapers: A History of the World’s Most Extraordinary Buildings.

Dupré – whose book, appropriately, is tall enough to reach an adult’s kneecap – says “they’ve always been a way to create national identity and national pride. And China, having been buffeted about by the pandemic and having had their national identity bruised, is saying: ‘No more copycat buildings. We are going to go back into our ancient and sophisticated culture. We’re going to go back to our own architectural and aesthetic groups and create our own constructed identities.’”

Dupré cites the new generation of Chinese skyscrapers styled after pagodas, of which Taipei 101, completed in 1999, is a well-known early example. These are part of a worldwide trend for buildings that are not just tall, but which trumpet cultural heritage. 

Take the Makkah Royal Clock Tower in Jeddah, Saudi Arabia, which looks a little like the Big Ben-housing Elizabeth Tower, but six times as tall (601m/1,972ft) and overlooking Mecca. Built to accommodate wealthy pilgrims and finished in 2012, the tower has the four largest clockfaces in the world, adorned with Islamic artwork and topped by a 35-tonne crescent moon. 

The clocktower’s 21,000 flashing lights, visible from 18 miles away, signal the time for prayer. The structure’s enormous height makes it the third-tallest skyscraper in the world, far outstripping other nationally-specific skyscrapers such as Dubai’s Burj al-Arab, which resembles the sail of an Arabian dhow ship. Then again, the Oblisco Capitale Tower, a mooted 1km (0.62miles)-tall, Ancient Egyptial obelisk-inspired centrepiece for Egypt’s new administrative capital, would, should it ever be built, be taller than both of them put together. Such is the future of international skyscraper-building, a field in which it is no longer enough to be supertall.

Does this mean the end, then, of the glass-and-steel cuboid? Not really. For one, characterful alternatives such as those above are government-backed one-offs rather than the commercially-minded projects that comprise the majority of skyscraper-building.

They are arising not so much in the West, which has pre-existing grand architectural aesthetics, as in countries that are interested in using architecture to exhibit themselves globally. And the cuboid form has reached new levels of refinement, notably in the startlingly slender high-rises that are beginning to populate Manhattan. The slimmest of these is the Steinway Tower, also known as 111 West 57th Street.  It is 435m (1,428-foot) tall and a mere 18m (60ft) wide. These needle-style skyscrapers owe their existence partly to their designers’ creative use of small plots, and partly to advances in engineering. 

To work out how best to meet challenges such as high wind speeds, engineers are making increasing use of artificial intelligence, whose application in this case involves a computer analysing data on wind speed and other variables, using it to workshop different designs. 

They are using stronger concrete to their forebears too, often fortified by industrial by-products such as slag from steel mills. These are some of the advances that underpin New York’s super-skinny skyscrapers, a cohort that, like their blockier predecessors that made the Manhattan and Chicago skylines so famous in the 20th century, are likely to inspire imitation elsewhere.

These advances also underpin that other great endeavour of skyscraper-building – to some, the only endeavour of skyscraper-building – height. More specifically, being the tallest in the world. That title, remember, is held by the Burj Khalifa in Dubai, whose height of 828m/2,717ft appears newly meagre when compared to the approximate 1km (3,280ft) height expected of Saudia Arabia’s Jeddah Tower. 

This is a preposterous step-up in height. The Jeddah Tower, whose elegant, glassy taper makes it look like the Shard’s much bigger brother, will be the tallest building in the world by the length of one and a half football pitches – if it’s ever finished. Work stopped in January 2018, less than a quarter of the way through the project, after some of its backers were arrested during Crown Prince Mohammed bin Salman’s purge of Saudi elites.

There has been suggestion that work will resume this year. Should that be the case, and should the Tower be completed, its hold on the world title will be temporary. The accolade of world’s tallest has already changed hands thrice since the turn of the millennium. 

You don’t have to be a Freudian to see skyscrapers as the most obvious symbol possible of national vigour, and, as Dupré points out, we humans have evolved to enjoy height independent of its value in outshining our rivals. “One of the things that human beings like, and have liked since primeval time, is height. Height allows for a long vista, letting us see whoever is approaching, whether it’s a group of enemies or wild creatures.”

Nature did not inscribe this instinct on our minds for the sake of tall buildings, but that is the effect of this programming. We like to see the lay of the land, and although the upper reaches of our tallest skyscrapers are far too high for us to see much detail in the ground below, we still have the ability to indulge these instincts further and build even higher.

As a building’s height increases, so do the challenges of building it. Apart from the colossal quantities of building materials and manpower, these projects entail increasingly complex technological problems. Lift cables can only be so long – enough for a 500m vertical run if they’re made of steel, 1km if they’re a cutting-edge carbon fibre alternative – before they become so heavy they cannot be raised.

To get to the top of the Jeddah Tower, you will need to take at least two lifts, and these lifts will have to travel at slower speeds than in other skyscrapers in order for their passengers to avoid suffering from the nausea of the 10 per cent reduction in air pressure. 

The higher you build, the greater the windspeed, and the tougher it gets to keep the building from perceptibly wobbling. All this presumes you can overcome construction challenges such as pumping concrete 500,000 cubic metres of concrete up a 1km tower. Oh, and you’ll need to mount a crane on your half-built, wind-lashed tower too – how else will you top out? 

Adrian Smith, who, as half of Adrian Smith + Gordon Gill Architectural Practice, co-designed both the Burj Khalifa and the Jeddah Tower, has said in the past that he thinks current technology can build to a mile high; William Baker, who led the structural engineering on the Burj Khalifa, has mused in an interview that “we could easily do a mile”, and perhaps much more, depending on the size of the base.

Given that buildings, being mostly hollow, are lighter than rock, “you could conceivably go higher than the highest mountain, as long as you kept spreading a wider and wider base.” Whether humans could ever reach such heights without suffering extreme discomfort is hard to know. What we can be sure of is that humans will invest gargantuan resources in testing all these boundaries.

The spectacle of yet taller skyscrapers is an appalling one to environmentalists. Some of the newest megatalls are net-zero, meaning that they generate at least as much energy, via facilities such as wind turbines and solar cells, as they need to run. The classification of net-zero, however, doesn’t account for the environmental cost of building the thing. Construction, according to some estimates, is responsible for around 40 per cent of global energy use. Most of this energy expenditure comes from the manufacture of concrete and steel, materials without which almost every high-rise in the world would have been impossible to build.

One exception is Mjøstårnet, a mixed-use Norwegian building completed last spring. At 85.4m (280 ft), it is barely half the minimum height (150m/492ft) required for a building to be classified as a skyscraper. But it is nevertheless remarkable, because it is the world’s tallest wooden building.

Of all the likely changes in skyscraper-building over the coming years, says John Klein, “timber has the ability to make the greatest impact.” This is thanks to the innovation of various kinds of mass timber – thin layers of wood glued together – that allow builders to construct much more durable wooden buildings than was previously feasible. 

Klein, an architect who is the CEO of Generate, a sustainability-minded architecture firm, is attracted to mass timber principally because it is a carbon sink: it absorbs more carbon than it releases. In environmental terms, it is wildly better than traditional building materials. In structural terms, it performs comparably well to steel despite being five times lighter. And in human terms, says Klein, wood is as good as it gets. “In a post-Covid world,” he says, “we realise the importance of healthy environments. And in the selection of materials, a space can help promote not only physical wellbeing but mental wellbeing. There’s a lot of interest around using these timber assemblies in building because you achieve this sort of biophilic sense.”

Biophilia is a word that describes humans’ innate affinity with the natural world, and there is a good body of evidence, to which Klein refers, that being around wood is good for us. The strongest of these benefits occur in woodland and forests, but wood as a building material seems to have a comparable effect. Children whose classrooms include exposed wood seem to study better. The rest of us feel less stressed in these surroundings.

The mechanisms are less clear, but the general rule is broadly accepted. Most of us know innately that wood is uniquely pleasant to the hand and eye, and the construction industry is catching up. As well as in Norway, there are towers made of timber – “plyscrapers” – in Canada and Norway. Last year, there was even a proposal for one in London.

At 300m (984ft) tall, Oakwood Tower would have been taller than any other British building except the Shard. It was only a concept, says Ron Bakker, founding partner of PLP Architecture, which co-designed the building, but the project was an informative one. 

The architects had sought “to work out the possibilities of timber structures for that sort of height,” and “the result was that it works, which is really good to know, and that it behaves well, and that the foundations were somewhat easier [than a steel and concrete building because it is so light.”

As it stands, a building like Oakwood Tower could not be built on British shores. After the Grenfell disaster, planning authorities clamped down on wooden buildings. “Regulations don't distinguish between mass timber and normal timber,” says Bakker, “even though their flammability really varies.” No corners should ever be cut in fire safety, he says, but mass timber has been recognised in other countries, including France and Spain, as appropriate in large buildings. Because it is so thick and dense, it performs well in fire safety tests, charring on the outside but remaining uncompromised within for hours.

In contrast, says Bakker, when a fire department has to deal with a big fire, “they have trouble going into a steel structure building because the behavior of steel in fire is very unpredictable. It might buckle at any time. The building then collapses and it's not a safe place to go into.”

There are other advantages to mass-timber. Architects are particularly excited about its potential for pre-frabrication: because it is light and portable, mass timber can (unlike concrete) be made into building parts before they arrive at the site, which saves city-centre sites a lot of time, noise and traffic.

This means that these projects go up quicker and more quietly. Mass-timber buildings, or at least hybridised mass-timber buildings that also incorporate steel, therefore look likely to play an increasingly important role in medium-rise buildings and perhaps high-rises too. Their green credentials depend on good forest management, but overall they seem our best hope of reconciling our need to build with our need to reduce our emissions. And the more natural-seeming our environment, the more we seem to enjoy it.

But why stop at wood? The field of biomimicry is yielding some fascinating glimpses into what the future might hold. Michelle Oyen, an associate professor of biomedical engineering in the department of engineering at East Carolina University, believes that bone is a highly promising building material.

Oyen’s work on bioengineering required her to help make new bone and cartilage for people with injuries or cancer, and it was this work that prompted her to wonder whether she and her colleagues had in fact been fabricating something that could be used in construction as well as medicine. “The mechanical properties of bone and wood are actually quite similar when both materials are dried out,” she says, “which is the state that they would be in when you would build something out of.”

The process of synthesising bone is currently laborious. At Prof Oyen’s old lab in Cambridge, they managed it by using a robotic Lego arm to dip a substrate, again and again, into one beaker that contained collagen and another that contained calcium and phosphate. This could be scaled up, Prof Oyen says. Our ancestors used the bones of woolly mammoths to create huts – could our descendants use synthesised bone to create light and durable skyscrapers?  “I don’t know why not, quite frankly,” says Oyen.

She and her colleagues have also looked at eggshell, which they also regard as promising. Chickens, Prof Oyen points out, create this tough substance out of ingredients as basic as corn, and they can produce an entire egg in only 18 hours and – unlike, say, steel – under normal temperatures.

Other groups have looked at the mother of pearl layer in seashells, wool and seaweed-reinforced bricks, fungi-based building blocks and more. The performances of these substances vary, and a huge amount more work is needed for these ideas to get anywhere near a blueprint. Materials that evolved over millions of years, it seems, might yet be something like as useful as the materials that humans have been using for a comparative blink of the eye. It is conceivable that the era of steel and concrete could be a blip.

“For many, many, many millennia,” says Prof Oyen, “the world existed without steel and concrete being the be-all and end-all, and then for these past couple hundred years, we’ve built everything out of those things. We realise we're about to destroy the planet, we rethink things, and maybe go back to a slightly different way of doing things.”

There are other, more immediate trends in the world of skyscraper construction. Sheer glass walls became fashionable for their ability to unobtrusively reflect the sky and let lots of light in, but are increasingly seen as passé. External masonry – which was, through buildings such as the Empire State Building, the form in which skyscrapers were born – is becoming fashionable again.

Elsewhere, more outlandish ideas are appearing, such as South Korea’s Tower Infinity. When completed in 2023, it will be encased in a sheath of LED lights that, between them, will give it the illusion of invisibility. 

Wright argues that buildings currently regarded by many as naff, obnoxious or boring will, in time, be more affectionately reappraised. This principle, he says, “applies to everything – those council tower blocks, the social housing blocks, which have been hated for so long but are now coming back. Some of them are getting converted into, you know, private apartments and trendy living places. This will inevitably happen to all of the bland glass skyscrapers that are going up right now. I think we're getting a little bit tired of them theoretically. But I think we may look at them differently in 20 years' time.”

That might depend whether the emerging trend for biophilia is a fashion – in which case it, too, will have its moment and then fade – or the uncovering of something inherent and timeless in the human psyche.

This possibility, which is far more enchanting than any of humanity’s unrealised fantasies of building bigger, bigger and bigger, is starting to be acknowledged.

In Singapore developers are forced to include copious greenery in their plans. Their new skyscraper designs are festooned with vegetation, inside and out. In Milan, the balconies of the Bosco Verticale’s twin towers are home to 800 trees and 14,000 plants. London’s Walkie-Talkie appears from the outside to be just another engorged office building, but contains London’s highest public garden. 

The green shoots of architectural biophilia are beginning to show.

• The Future Of... is a longread series published on Thursdays at 8am. Previous chapters explored the future of meat, the future of the country pub and the future of female friendship. Return to Telegraph.co.uk next Thursday for the next instalment

• Do you work or live in a skyscraper? Which do you like, which do you despise? Would you welcome wooden supertalls to our skylines? Have your say in the comments section below.