It is rare in the history of architecture for a new type of building to emerge. The Romans’ discovery of concrete birthed the great domes and fortifications of its empire. The Victorians’ development of steel led to an era of majestic bridges and vaulted train sheds. The American invention of the elevator created the first skyscrapers in Chicago. Now, we are seeing a new type of structure that perfectly embodies the 21st-century age of technical ingenuity and extreme inequality. A heady confluence of engineering prowess, zoning loopholes and an unparalleled concentration of personal wealth have together spawned a new species of super-tall, super-skinny, super-expensive spire.

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Any visitor to New York over the past few years will have witnessed this curious new breed of pencil-thin tower. Poking up above the Manhattan skyline like etiolated beanpoles, they seem to defy the laws of both gravity and commercial sense. They stand like naked elevator shafts awaiting their floors, raw extrusions of capital piled up until it hits the clouds.

These towers are not only the product of advances in construction technology – and a global surfeit of super-rich buyers – but a zoning policy that allows a developer to acquire unused airspace nearby, add it to their own lot, and erect a vast structure without any kind of public review process taking place. The face of New York is changing at a rate not seen for decades, and the deals that are driving it are all happening behind closed doors.

The results range from the sublime to the ridiculous, or even both at once. There is 432 Park Avenue, a surreal square tube of white concrete that appears to shoot twice as high as anything around it, its endless Cartesian grid of windows framing worlds of solid marble bathtubs and climate-controlled wine cellars within. It is the most elegant of the new towers, recalling the minimalist sculptures of Sol LeWitt, although its architect, Raphael Viñoly, says it was inspired by a trash can. He can clearly turn garbage into gold, given the penthouse sold for $95m (£72m).

It is the tallest residential building in the world, but it won’t be for long. The sturdy trunk of Central Park Tower is rising nearby – a great glass hulk that will soon steal the crown for the most vertiginous residences on the planet. Designed by Adrian Smith and Gordon Gill, architects of Dubai’s Burj Khalifa, the tower will form a dizzying stack of superlatives, with the biggest pools, highest health club and farthest-reaching views in town. You might even be able to peer into your neighbouring oligarch’s flat, given how close the next-door tower is squeezed.

Standing right across the street, 220 Central Park South aims to be the gentleman of the bunch. A neo-art deco tower clad in silvery Alabama limestone, with set-back terraces and ornamental metalwork, it is the work of Robert AM Stern, expedient purveyor of whatever style his client wants, from Spanish revival to Qing dynasty. “Architecture is a banquet,” Stern tells me, “and most architects are starving to death.” He says that “unlike some of its neighbours now under development”, his design “will belong to the family of buildings that have framed Central Park for generations”. The dapper costume has paid off: some apartments in his tower have gone for more than $10,000 per square foot. The penthouse was recently acquired by a hedge-fund billionaire for $238m, making it the most expensive home ever sold in the US.

Form has always followed finance in New York, and this latest architectural byproduct of excess global wealth is no exception. Building very tall has been technically possible for some time, but it hasn’t made much commercial sense: the higher you go, the cost of building often exceeds the returns. That is, until now.

Like leggy plants given too much fertiliser, these buildings are a symptom of a city irrigated with too much money. The world’s population of ultra-high-net-worth individuals, a super-elite with assets of at least $30m, has now mushroomed beyond 250,000 people, all in need of somewhere to store their wealth. More than a third of them are based in North America, while those from riskier economic climes favour New York real estate as one of the safest places to park their cash.

Since the 2008 global financial crisis, luxury housing has become a new world currency, providing investors with both a tangible asset and a certain cachet that can’t be found in stocks and hedge funds. The continued volatility of financial markets has spurred buyers to seek safe havens in super-prime real estate, from London to New York and Hong Kong, begetting stratospheric prices and minting a whole new category that defies the usual rules of the marketplace: the “trophy property”.

Sitting alongside rare wine, coloured diamonds and old masters, a full-floor apartment in a pencil tower with a view of Central Park makes a fine addition to the investor’s trophy cabinet. Except it is not just a trinket in a safe. It is a very large presence on the skyline for all to endure.

The impact of this new species of tower hasn’t gone unnoticed by the Municipal Art Society of New York (Mas), a non-profit organisation that has been campaigning to protect the character of the city since the 1890s. They have published a series of Accidental Skyline reports over the last few years, lobbying for the planning process to be opened up to proper scrutiny.

“The first time most New Yorkers heard about this new crop of towers was when they saw them under construction,” says Tara Kelly of the Mas. “They are mostly built ‘as-of-right’, meaning the developers don’t need planning permission and they don’t need to notify anyone. There was no public review and no community engagement, and yet these buildings will be casting huge shadows across Central Park for years to come.”

Complaining about shadows in a city of skyscrapers might sound perverse, but Mas has a long and illustrious history of battling shadows and shaping the form of New York.

The group was instrumental in passing the city’s first zoning laws, spurred on by the arrival of the Equitable Building in 1915, a 40-storey stone Goliath that filled an entire city block in Lower Manhattan and rose hundreds of feet up from the sidewalk. It is now a cherished landmark, but at the time it was monstrously out of context – a great mountain that blocked the flow of air, dumped thousands of pedestrians on to the narrow pavements and cast a seven-acre shadow over the neighbourhood.

Facebook Twitter Pinterest The tower at 432 Park Avenue in New York. Photograph: dbox/CIM Group & Macklowe Properties

The following year, the city adopted the 1916 Zoning Resolution to regulate the massing of buildings, incorporating “setback” requirements to allow more light and air to reach the street. The code introduced the idea of the “sky exposure plane”, an imaginary envelope that slopes back from the street at a designated angle, which a building cannot penetrate, forcing towers to step back as they rise. In the 1920s, architectural draughtsman Hugh Ferriss created a series of dramatic perspectives to demonstrate the sculptural consequences of the zoning law, depicting progressively chiselled volumes, resulting in what would become the classic style of the golden age of skyscrapers.

Little changed until 1961, when the zoning resolution was overhauled. The concept of floor area ratio (FAR) was introduced as a tool to control bulk and density, setting a maximum ratio of the building’s total floor area to the size of the lot. An FAR of 10, for example, means you can build 10 times the floor area of the lot, in whatever configuration: a 10-storey building that fills the lot, or a 20 storey building on half the lot, etc.

The revamped laws also introduced the curious notion of transferable development rights (TDRs), also known as “air rights” – a mechanism that allows landowners to buy the unused air space of their neighbours and add it on to their own lot. It is the ultimate free-market planning clause: if your neighbour is not exploiting their potential to go skywards, you can buy it off them and make your building even taller. It seems fitting that in the cut-throat capital of capitalism, even the air is for sale.

Crucially, the law specifies that the properties must share at least 10ft of boundary, but there is no limit on how many connected lots can be assembled, leading to a situation where a developer can snake their way around a block, piecing together a complex jigsaw puzzle of adjoining lots, buying up neighbour after neighbour’s spare air in secret. It has become one of the most lucrative currencies: in some cases, developers have paid the same price per square foot for air rights as they did to buy the land itself.

Another law, introduced in 1968, allows designated landmark buildings to sell their air rights across the street or down the block, spawning odd little-and-large pairings around the city. It was intended as a means of compensating historic buildings for the potential financial losses stemming from their landmark status (which severely restricts alterations), and allowing the city to skirt any financial responsibility itself. The result is a very New York scenario: great megaliths loom above tiny historic fragments, perversely protecting them in perpetuity in the process.

Facebook Twitter Pinterest A graphic showing 159 sites in Manhattan that could potentially accommodate a residential skyscraper of 600ft or taller. Photograph: KPF Urban Interface

Such Faustian bargains are nothing new. In the 1970s, Donald Trump paid $5m for the air rights above the landmarked Tiffany building on Fifth Avenue, which, along with various other deals, allowed him to inflate what would have been a 20-storey building into the 58-storey Trump Tower. Twenty years later, he stockpiled air rights from at least seven low-rise properties in Midtown Manhattan and piled them up to create the 70-storey black glass box of Trump World Tower.

But these negotiations pale in comparison to what has happened over the last decade. The parade of poles that have sprouted along 57th Street (AKA Billionaires’ Row) on the southern edge of Central Park, represent some of the most fiendishly complex and aggressively litigious dealing the city has ever seen. Gary Barnett, founder of Extell Development Corporation, took 15 years to assemble the property and air rights for One 57, one of the first of the new generation of super-tall residential towers, a garish blue-speckled shaft designed by Christian de Portzamparc, completed in 2014. He took another decade negotiating nearly a dozen further acquisitions to put together the 1.2m square feet of development rights he needed to build Central Park Tower. It was probably time well spent: the project will reportedly have a total sales value of $4.4bn, making it the most expensive residential building in New York’s history. “Our strength is assembling land,” says Barnett. “On that, we’re Number One.”

Part of the assembly involved the controversial acquisition of the air above the neighbouring Art Students League, an elegant French Renaissance-style building from 1892. In order to get the best views of the park, the tower now cantilevers out over its neighbour, a 400-metre cliff face of luxury flats hovering ominously above its decorative stone balustrade. The strange pairing will forever stand as a typically Manhattanite monument to the messy compromise of development-rights trading.

A few doors down to the east stands a similarly odd couple. The newly restored white limestone facade of the 1920s Steinway Hall, where Sergei Rachmaninoff, Nina Simone and Marvin Gaye all played, now cowers at the foot of one of the most audacious structures ever conceived.

The former piano showroom and recital hall will soon serve as the luxury health club for residents of 111 West 57th Street, a 435-metre tall, 18-metre wide wafer of a building. With a slenderness ratio of 1:24, it is set to be the skinniest skyscraper in the world. Try making that stand up in gale-force winds.

“The 800-tonne tuned mass damper helps,” says Chris Sharples of SHoP Architects, the firm responsible for the design, referring to the gigantic weight at the top of the tower that will help to stabilise the building. Making this gossamer-thin strip of a tower stand up has some strange consequences inside. In order to leave the north and south facades open for uninterrupted views, the two bracing concrete side walls are up to a metre thick, creating deep arrow-slit windows – perhaps an appropriate aesthetic for these fortified luxury bunkers in the sky.

Right out of one of Hugh Ferriss’s drawings, the tower’s tapering silhouette is a literal expression of the required set-back angle along 57th Street. (The developers even hung a Ferriss-inspired image of the building over the scaffolding, perhaps the first time a planning diagram has been used as a marketing tool.) But rather than stepping the building back in big chunks, the architects have reduced the mass in slender increments, giving it the feathered look of a quill pen. They have taken inspiration from New York’s cherished skyscrapers of the early 20th century, such as the Woolworth and Chrysler buildings, cladding the concrete side walls with panels of moulded terracotta and bronze, which form shimmering waves when seen from the street below. It is one of the few hyper-luxury apartment buildings that actually has the ethereal aura you would expect – a fitting costume for the eyrie of an untouchable elite.

Facebook Twitter Pinterest A CGI rendering of the future Manhattan skyline around Central Park. Photograph: Ondel Hylton/cityrealty.com

“We were thinking the very top would make a cool aviary,” adds Sharples, “but it doesn’t look like that’s going to happen.” There may be no aviary, but there is practically everything else.

To stand in the show apartment across the road is to be transported to another realm. A miniature bronze model of the tower serves as the apartment’s front door handle, which turns with an expensive clunk to reveal a lair of untold opulence. It is a place where the walls of his-and-hers dressing rooms are covered with leather and velvet, where sinks are carved from solid blocks of Italian onyx, where walnut drawers are lined with ostrich skin.

“We’ve used the most expensive and hard-to-find stone in the world,” says Michael Stern, founder of JDS Development Group, as he pats one of the solid marble kitchen counters. A thick-set 39-year-old with a soft Long Island accent, Stern makes for a disarming luxury real-estate tycoon. He is a passionate enthusiast for the city’s architectural history, and seems genuinely eager to add to the canon. He extolls his tower as a monument of world firsts, from the acres of rare book-matched stone and timber to “the most complicated facade ever attempted”. Leading me around the palatial apartment, he points out how the shower doorframe is made of solid bronze, how the kitchen cupboards are single pieces of curved glass, how the spiral staircase has solid stone treads. At least the weight of all the marble should be enough to keep the tower from tipping over.

So what does Stern make of the criticisms that these silos of billionaires are casting ever-longer shadows across Central Park, and that the negotiations happen well away from public scrutiny?

“The shadow argument has been debunked completely,” he insists. “Shorter, blockier buildings cast bigger, long-lasting shadows than tall slender buildings, which have longer shadows that move more quickly. If all of the air rights were built out in slender towers, rather than blocky buildings, the shadow impact would be much less. The density is finite, so isn’t it better that it’s used in a taller, slender building, rather than a short, fatter one?”

As for the lack of public review, he is adamant that it is the foundation of the city’s success. “One of the great things about New York, compared to other cities, is that, as a developer, you can rely on as-of-right zoning: there is a certainty about your building rights. What makes the economy go is the fact there isn’t a discretionary review of everything.” When I raise the opacity of air rights transfers, and the problem that no neighbour knows who is selling, or if they will see a 30- or 90-storey tower as a result of their sale, he grins: “That’s part of the game of assemblage.”

This love of Manhattan’s no-holds-barred market logic is shared by Carol Willis, director of the city’s Skyscraper Museum, which staged an exhibition on the super-slender towers when they first began to appear in 2013. When asked in an interview if there should be any change to planning policy in response to the rash of super-talls, her response was immediate: “No, absolutely not.”

She says campaigners fail to understand that these towers “will not add one single square foot of built density to the city”, given that allowable density is finite. “It’s a cap-and-trade system,” she says, so once air rights are transferred from a low-rise lot, it will stay low for ever. The rules merely allow potential floor area to be shifted, not created.

As for the accusation that the buildings will remain empty, sold to a class of people who won’t live in them anyway, she makes an interesting comparison with London, where swaths of Kensington and Chelsea stand eerily quiet for much of the year, having been flogged off to overseas investors.

“Concentrating more people, even if they’re billionaires, in towers to keep neighbourhoods tight and active is a much smarter way to add space to the city,” she says, “rather than to displace people on the ground plane and move them further out … The problem of people having more money should be addressed by taxes and public policy, not by restricting purchases on multi-million dollar apartments.”

Facebook Twitter Pinterest The Billionaire’s Bunker at 220 Central Park South. The penthouse recently sold for $238m, the most ever paid for a home in the US. Photograph: Timothy A Clary/AFP/Getty Images

New York’s inclusionary housing policy goes a small way to redressing the balance: developers can build taller in exchange for funding affordable housing elsewhere. Like the UK’s Section 106 agreements, the policy allows at least some bounty to be creamed off from these steroidal totems for the public good. Central Park Tower, for example, gained 90,000 sq feet after it bought the rights from another developer’s affordable housing scheme, while JDS contributed $9m to affordable housing in return for a bonus of 20,000 sq ft at 111 West 57th Street.

A good deal of extra height can also be added to these super-talls simply by leaving gaping voids in the body of the towers. While the zoning system places a cap on floor area, there is no limit on the actual height of each floor, nor are technical floors counted in the FAR calculations. The result is huge areas devoted to “mechanical” space: 432 Park Avenue enjoys more than 90 metres (300 linear feet) of mechanical void, while 111 West 57th St has a 85ft-high ground floor lobby. As Michael Stern puts it: “There’s a finite amount of floor area you can work with, so we shed it from below and put it up top.”

The city planning department has remained steadfast against calls for further transparency, although pressure for change is growing in some quarters. In October 2018, a city council member introduced a new bill to require the department of parks and recreation to “establish a task force to study the effect of shadows cast on public parks by buildings constructed in the vicinity of such parks”, something that Mas has been advocating for years.

Many in the industry say any such measures are too late to the game – that the super-tall boom has already reached its peak, and the available air rights have been used up. But detailed analysis by both Mas and KPF shows that is simply not true. There are millions of square metres of unused development rights remaining across New York, and around 100 sites that could still accommodate a super-tall tower.

Mas is tracking more than 100 proposals for super-tall towers (taller than 180 metres) in the pipeline, from a Russian-backed project at 262 Fifth Avenue – likely to block views of the Empire State building from Madison Square Park – to 80 South Street, a vertiginous needle for Lower Manhattan, whose 426,000 sq ftof air rights account for almost half its height. There are many more on the way. Brooklyn is the latest battleground and even Harlem is being touted as the next frontier.

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It is important to remember that most of New York’s cherished skyscrapers were greeted with dismay when they first appeared, and there are some architectural marvels amongst the latest crop of towers. But as the gap between the city’s rich and poor yawns ever wider and residents are being pushed further out of the city, with public housing is on its knees, it could be time to interrogate the unexpected impact of the 1960s zoning laws, 60 years on.

There are some simple steps that could make New Yorkers feel they have a say. Mas has called for community boards to be notified when air rights transfers occur, and has suggested a public review for transfers above a certain threshold. There could even be a limit on how much of the city’s air you can buy. “We don’t object to any one of these buildings in particular,” says Tara Kelly. “The process is our main concern. We could talk about what the skyline means, about shadow impacts, about how much luxury housing we think is appropriate when we’re in an affordable housing crisis. There would be a forum for all those voices. As it stands, there is zero.”

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• This article was amended on 7 February. An earlier version said Trump Tower has 68 storeys. It is billed as such, but in fact has only 58.



