In London, skyscrapers are time capsules. Whole emirates can spring from the desert and become old hat in the time it takes to carve a notch in the capital's skyline, so arduous is the planning process. The towers being completed today are the architecture of a decade ago, rising in a changed landscape, a different city. Their success or failure is a wild gamble.
This year's bumper crop of tall buildings is the product of economic conditions years before the Iraq War and the iPhone. So there's not necessarily a contradiction when architect Ken Shuttleworth, founder of Make, looks upon these new shoots and says, as he did in April, "the tall glass box is dead". Shuttleworth made his name with a tall glass cylinder, the cucumboid Swiss Re tower, approved in 2000 and completed in 2004. The Heron Tower and the Shard, it is bizarre to note, are part of the same generation of buildings as the Gherkin, sketched out in the Millennial enthusiasm of tower-keen Ken Livingstone's first term as mayor. A decade has passed, during which Shuttleworth's Gherkin has been warmly admitted into the city's idea of itself; all that time the Heron and the Shard were picking their way through inquiries and hearings, appeals and decisions, cold feet and unexpected reprieves. Terrorists struck New York and London. Two mayors and three prime ministers oversaw the process. And here they are.
The arrival of these new giants on the skyline is a substantial change to London, a city that mostly changes very gradually. Few of us will be fortunate enough to live or work in the Heron or the Shard, although they will have public restaurants and viewing decks. Mostly, however, they will be consumed from the street, as objects or sculpture, components in a view, elements in the city's scenography. So we took sculptor and repository of London lore Richard Wentworth on a walk through the City, from Liverpool Street Station in the north to London Bridge Station in the south, to assess the new London as sculpture. And between the capital's new tallest buildings is another new tower that barely appears on the skyline at all – it's nearly a secret.
But first there's the Heron, anything but a secret. Designed by architect Kohn Pedersen Fox for property developer Gerald Ronson, the Heron cost £242m – it has to be a landmark in order to attract tenants. And it's three or four landmarks for the price of one, articulated to appear quite different according to your angle of approach.
From the east and west, it's a tiered spike; from the south a humdrum glazed slab (although this will matter less with the completion of the Pinnacle, another late-flowering tower in the City's intended cluster of tall buildings). Its north face, however, is a ladder of beefy steel cross-bracing, a bit of unabashed machismo. This is the angle that Wentworth likes best: "It's the thing that takes you to the top, as staircases do, as zagging does." Otherwise, "It's not a building you would want to sleep with ... I would never take someone to see it."
From the pavement outside, however, it has another element of sculptural appeal. The triple-height atrium is dominated by an enormous fishtank in cast acrylic – 70,000 litres of water that will soon house 1,300 fish, including three sharks. A bus-sized bridge of artificial coral can be seen from the street. "It's very exciting that people can have big train sets," says Wentworth of the tank, attributing this bold use of an aquarium to Damien Hirst's embalmed marine animals. We ask to go into the lobby, so Wentworth can get a better view of the mighty fishtank, but are politely rebuffed by a bowler-hatted giant. Not today, maybe next week. "That was one of those moments, where you just know that you've run out of public space," says Wentworth. And while the glass and steel language of office buildings can suggest openness, democratic transparency and internationalism, the signature architecture of 21st-century London is, sadly, this street-level fortification. And the cranking up of security on the street changes the way we behave. "We know fortified space when we see it, we know defensible space when we see it," says Wentworth, "and we move decorum up and down in relation to it." On a previous tour of the Heron, I learned that the fishtank conceals an airport-style security screening and X-ray area.
The City is very small – it takes just a couple of minutes on foot to get from Bishopsgate at its edge to the Bank of England at its centre. You have to position yourself carefully to see New Court from Bank – in fact it's hard to see it from anywhere. New Court is OMA's new headquarters for Rothschild, the venerable and august merchant bank. It's on St Swithin's lane, a tiny thread in the City's medieval lacework, and behind the Mansion House and a Wren church, St Stephen's Walbrook. At ten storeys, the new HQ, due for completion later this year, is relatively tall for its super-sensitive location. But it is so cunningly insinuated into the surrounding urban fabric that it can only be seen from a few choice angles – and even then it's near impossible to see in its entirety. The double-storey glazed box at its top can be seen here and there poking above rooflines; elsewhere the striped metal and bluish glass facade is mostly seen slice by slice down alleys. It's very City, and the facade will inevitably be compared to a pinstripe suit when the building is written up – if it ever is, as the client has little need or desire for publicity, something that is also very City.
"It's quite gentlemanly, I think, like a nicely made small Merc or BMW," says Wentworth of New Court. "I think it's the way that it's ... it's not inserted, it's slightly nudged into the City but without being apologetic. And its little structural symbols, the hints at decoration in the facade ... [are] the most interesting calligraphy I've seen this morning, and I look at buildings' calligraphy as much as I look at their graffiti." And for all its privacy, there's a sense of patronly generosity at the foot of New Court – a tiny City garden links with a courtyard running under it, a thread of public space that will run though the site.
In the dense streets of the City, the Shard can only be seen in snatches. But when we reach the river it dominates the view, and Wentworth compares it in vigour to the 19th-century industrial buildings on the riverfront. The Heron is the tallest building in the City, but the Shard is the tallest building in the European Union, combining luxury apartments, viewing decks, a hotel, a spa and office space. It will be a "vertical town", used by 10,000 people every day, architect Renzo Piano told the London Evening Standard's ES magazine. "The building will become part of London because everybody will visit and mix; that is the nature of good cities," the architect added, in a twinkling little banality.
Banal and, in fact, quite wrong. The Shard won't become part of London. It is already part of London. The computer images of the finished building, from every angle, above and below, night and day, have so thoroughly driven the spike home that some Londoners believe that it's already complete. As the steelwork climbs the 72-storey concrete lift core, the Shard is making the transition from one state of unreality to another, from hallucination to a kind of invisibility. If you don't believe it to be finished already, at present it's hard to believe it really exists, and a sudden glimpse of the jagged fang seen from a new and unexpected vantage point has the power to stop you in the middle of the road. But, quicker than we expect, it will be part of the scenery, the building that is flashed up in films to show that the action has moved to London, more visual metaphor than individual structure.
This is a potent moment, then, when opinion is setting around the tower. In the 1973 Martin Scorsese film Mean Streets, the unfinished World Trade Center makes an unexpected appearance near the end. Hindsight makes the Twin Towers look like the shape of things to come, the passing of Manhattan from Johnny Boy and Travis Bickle to Gordon Gekko, Sherman McCoy and Patrick Bateman. The Shard will date London, before and after; it will mean this moment as well as this city. Piano should be reassured that the omens are good. In February, the capture of an urban fox on the topmost floor of the Shard made national news and was front page of the Sun tabloid newspaper. Around the same time, leading local blog Londonist.com changed its logo, a stylised skyline, to include a Shard. The popular imagination is flexing to accommodate the tower.
At street level, in the maze around London Bridge Station, it's clear how the city had to flex to take the building. "This is a very contorted part of London, it's like when you get a wet tea towel and you get someone else to hold the other end and it twists against itself," says Wentworth of the South Bank. "Urbanistically, what defeated it was the railways – the railways arrived and the railways are a knot." The Thames bends tightly as it passes through central London. Bunched up on the inside of the curve, in south London, is a tangle of roads and railways serving the urban core on the North Bank. The area is the jumble of cables under London's desk, where infrastructure has been allowed to pile up beyond hope of serious rationalisation. In the early 2000s, then London mayor Ken Livingstone recast London's bigger rail interchanges as potential locations for clusters of tall buildings. The skyline would become a relief map showing network intensity. The Shard is the most significant product of that policy. The play of road and rail bridges in the streets around the Shard, surmounted by that slender spire, is thrilling, and intensely urban.
But, perversely, it's almost hardest to see when you're standing next to it. The biggest change to London will be from afar. Guardian art critic Jonathan Jones has registered his dismay at the way the spike appears to impale St Paul's cathedral when viewed from distant Primrose Hill. But from elsewhere, for instance Clerkenwell, the combination of spike and dome could not be happier, a composition reminiscent of the Trylon and the Perisphere at the 1939 New York World's Fair.
Wentworth places the unusual care that London takes in managing its skyline and views in the tradition of the English landscape garden, and landscape designers like Humphry Repton's use of "eyecatchers" placed invitingly in a picturesque setting. But, as we stand at the base of the Shard, he also relates the Shard to another turn-of-the-century South Bank building, the Tate Modern, and Tate director Sir Nicholas Serota's use of art as urban spectacle. "Event" museums like the Tate have enabled the permeation of monumental art into everyday life: "There are more and more things that are like art, there's furniture that's like art." And this fed the now-waning appetite for "iconic" architecture: "There's obviously a seething for shapes. And everyone's realising that there aren't all that many shapes." The Shard is the final triumph of the shape – now all we have to look forward to is the scroll-shaped Pinnacle and Rafael Viñoly's unpromisingly bulbous "Walkie Talkie" tower. (Although Southwark council called for further landmark buildings to capitalise on the "success" of the as-yet-unfinished Shard.)
Despite his own scepticism, Wentworth also has a mild warning for those who scorn the new towers. "The thing that's hilarious about people being possessive about the city is that it is in a kind of brownian motion," he says. You wouldn't apply planning permission to people or cars, to stop the less attractive using the street. "That kind of acceptance is part of occupying the knot. That doesn't mean you don't have an opinion about good and bad, or an opinion on different kinds of imposition, but it's not as if that isn't what the city is doing anyway."