Postmodernism is back, and this time it’s got much more going for it. London’s Young Vic theatre shows how.

Once in a while, you sense a change in the cultural atmosphere. It’s as if someone has flicked a switch in some distant room, and a process has begun: quietly, almost imperceptibly at first, but gathering pace and finally emerging into the open. When it starts to affect the buildings that shape our cities, then you know it is not going to go away. So it’s a big hello to the new Postmodernism.

The tectonic shift is apparent in two new, important cultural buildings, just opened. Both are long and thin, as it happens, but that is absolutely all they have in common. The first is celebrity art dealer Jay Jopling’s gleaming new White Cube gallery in Mayfair. Designed by the low-profile Mike Rundell, designer of choice for the Britart generation, it is the ne plus ultra of ultra-reduced modernism. In its way, it is historic. This is the kind of building the early modernists in the 1920s dreamed of. It is the kind of building architects Herzog and de Meuron, responsible for Tate Modern, used to do in their earlier, more Puritan, days. It is, for the moment, the end of a line.

Then at the other extreme you have the made-over Young Vic theatre in Waterloo. As recently as 2002 this temporary urban jumble, first conceived in the late 1960s, was going to be knocked down and replaced with a sleek glass-and-timber shoebox designed by the steadfastly minimalist John Pawson. It would have been expensive and more than a little good-taste corporate in feel. So the theatre had second thoughts, ditched Pawson’s scheme, and started again, looking to a younger generation. The result, by architects Haworth Tompkins, is revelatory. If anything in architecture is a manifesto statement, this is it.

In an extraordinary, almost alchemical process, the temporary Young Vic buildings put up by architect Bill Howell for £60,000 back in 1970 have been breathed on, augmented, enhanced, layered. The place has been taken apart and put back together in permanent fashion. There is much that is new, and some that is old. The miracle is that it is still, recognisably, the Young Vic. Although gentrification’s tendrils are now reaching even unto this ragged inland urban edge of London’s Waterloo/Blackfriars quarter, the theatre – always intended to be an incubator of new theatrical talent – has kept its necessary rough edges and acquired some new ones. Let’s call it personality.

The low-budget feel is all there, too. Go into the theatre’s administrative offices at the back and you find desks and storage made out of plywood, nuts and bolts. But done so well, you feel the system should be instantly marketed as an alternative DIY furniture product. Graham Haworth and Steve Tompkins cut their teeth years back doing a low-budget conversion of the old Ambassadors theatre for Stephen Daldry while they worked up to doing the Royal Court for him. They also built two dirt-cheap temporary theatres for the Almeida. These boys are jewellers of junk. They can make galvanised electrical conduit pipe look valuable, just by bending it in a certain way. They like to expose rough old walls and floors and leave them that way. Their fertile inventiveness is apparent all over the Young Vic.

But postmodern? That, to some ears, is an insult. And Haworth Tompkins are modernist by instinct. We all remember the excesses of the 1980s, we all know what Postmodern meant then. In architecture, 99 per cent of it was gruesome. It was essentially your standard modernist box with bits and bobs stuck on in the name of wit and historical reference. There were exceptions, but not many. From that era only one good postmodern building, and one almost-good one, got built in the capital: respectively the big fat hen of James Stirling’s Number One Poultry office building in the City of London – tolerated by many modernists because it was by the famous Stirling – and the ziggurat-fortress of Terry Farrell’s MI6 spymaster HQ at Vauxhall – generally sneered at because Farrell was seen as a turncoat rather than an experimentalist. Whatever, the new postmodernism is very different.

The decadence of 1980s postmodernism was purged by the recession of the early 1990s, after which a new generation of clean-cut modernists and minimalists and Haworth Tompkins – emerged. But eventually even pubs started going modern. The loft-living, polite-modern look, all steel, glass and polished wooden floors, became every estate agent’s stock-in-trade. And whenever a stylistic movement gets down to High Street level, you know that its days are numbered.

Although “modern” home furnishings retailer Habitat sponsored the Victoria and Albert Museum’s recent Modernism exhibition, it was already an odd fit: under its creative director Tom Dixon, Habitat had rediscovered variety and eclecticism: strong colours, patterns, textures. Commercially, Dixon probably made his move too soon: popular taste is still catching up with him. On the couture level, the achingly modish furniture company Established and Sons, run by Stella McCartney’s husband Alastair Willis, also embraces the new eclecticism: his company’s “Fold” lamp – a traditional table-lamp shape pressed out of sheet metal – is pure postmodern.

The style leader among Britain’s notoriously conservative housing developers is the multiple award-winning Urban Splash. Impeccably modernist for years, Urban Splash has dived gleefully into postmodernism for its latest, huge development: the New Islington urban village in Manchester. What with an apartment block like a pile of potato chips by Will Alsop, and social housing celebrating Dutch gables and Juliet balconies by inventive architects FAT – all wildly popular – it is apparent that the postmodern shift is not just some febrile London thing. Others are bound to follow.

But to get back to the Young Vic. It reminds me a little of the early Californian experiments of Frank Gehry, using cheap timber and chicken wire. The main auditorium is clad in cement boards, each individually painted by artist Clem ? These are then clad in turn by a screen of perforated aluminium – like a scaled-up version of the expanded metal you usually slap plaster onto. Tompkins explains that this is his equivalent of a theatrical gauze: opaque with the light in front of it, transparent with the light behind it. A brilliantly simple and effective device which transforms the building between day and night.

But there is more going on here than just a clever architect doing ingenious things with cheap materials. The Young Vic approach embraces and reveals the past – such as the old butcher’s shop which is still the main entrance to the theatre – while adding new spaces and new layers of history. Tompkins is happy to let the building mutate on its own terms. He doesn’t do icon buildings. Or not yet, anyway. And this is the difference between the new postmodernism and the old. This time round, it’s far less superficial, far more intelligent, and considerably less hysterical. I think we’re in for an interesting few years.

Text © Hugh Pearman. First published in The Sunday Times, October 15, 2006, as: “Where there’s junk, there’s class”. Photos by Philip Vile.