Click arrows above for a slideshow of Rafael Vinoly's designs

Two hours in and the architect Rafael Viñoly is only just getting going. We've done South American history, the credit crunch and Gordon Brown and are on to the philosophy of architectural aesthetics. “I like to talk,” he says, smiling.

He's a charmer, with smooth Latin looks, twinkling eyes, a strong accent and the endearing habit of wearing three sets of spectacles at once, like a forgetful grandpa. But it's the chat that wins you over. A good skill in his line of work, for this larger-than-life Uruguay-born New Yorker is in town to sell himself. Suddenly, despite 45 years in the business and as one of America's most famous architects, Viñoly seems to have crept up on Britain. We know Gehry, we know Libeskind, we know Zaha Hadid, and they've all barely built in the UK. But this major international player has real buildings being built here right now, and how many of you have heard of him?

First are two arts centres which, he hopes, will add “a panache” to their respective towns. You can't miss the crescent-shaped, gold-skinned First Site contemporary art gallery, floating above Roman remains in Colchester. The town has seen much in its 2,000-year history, but this is up there with Boadicea's rebellion. Already dubbed the “Golden Banana” and backed by the Tate's director, Sir Nicholas Serota, First Site, which will open in 2009-10, has an exotic zing just the right side of bling that characterises Viñoly's best work - the grand gesture of the “signature architect”, but the right gesture.

In Leicester, his Curve performing arts centre, opening on November 1, swooshes a go-faster striped glass façade round half a city block like wraparound shades. “Some theatre people have complained about our plans to open up rehearsals and back-of-house to public view through the glass,” Viñoly sighs, uncomprehending of British reserve. Still, the Curve's vast glass wall and canyon-like spaces make up in vigour what they lack in subtlety.

But these are just the hors d'oeuvres. For the main course, Viñoly is working on two of the capital's most controversial buildings. The Walkie Talkie skyscraper in the City of London and the third attempt to resuscitate Battersea Power Station. During the planning inquiry last year English Heritage called the Walkie Talkie the “ugliest and most oppressive building” in London because of the impact that its 160m (525ft) height and rounded profile - like a cordless phone - would have on the City's skyline. But the Commission for Architecture and the Built Environment praised its “significant architectural contribution”. Either way, the Government approved it.

Battersea is another matter. When Viñoly's designs for the latest, £4 billion plan were unveiled in June there was widespread disbelief. “I honestly thought it was a spoof,” the former RIBA president George Ferguson told Building Design. He spoke for a lot of people. There was something comic about its ridiculous, 300m chimney outchimneying the most famous chimneys in Britain. Had Viñoly missed the point? He does, he admits, find our sentimental attachment to the old building inexplicable. “If I showed you the letters they wrote when the building was being built - they f***ing hated it.”

It's the clunky design of the rest of the site that is more worrying: 38 acres containing a “power station for the 21st century”, says the developer, Treasury Holdings, run on bio fuels. A huge office park; 3,200 homes and, within the restored shell of the old power station, shopping malls, an hotel and a public park. Relax, says Viñoly. “These are just early ideas, they can easily change.”

The storm over the look of the place, he says, misses Battersea's main problem: “developability”. The site is vast, isolated, without good public transport connections. And any redevelopment has to fund the restoration of Giles Gilbert Scott's building - conservatively estimated at £150 million - before leaving the starting blocks. “People are not exactly queueing up to redevelop the place.”

What critics see as overdevelopment is, Viñoly contends, necessary to make the figures stack up. He has come up with the rough outline of what his clients want to make the place work. “If this doesn't happen, nobody saves that building.”

Such words betray Viñoly's pragmatism. Of all the architects I've met he is the most realistic about his profession. “Architecture doesn't have to be permanent. I'm perfectly happy to demolish anything. I don't mind,” he says. “Architecture is not just about pretty buildings. It's the whole deal. It's getting the buildings built.”

Viñoly has always been good at getting buildings built. In the mid-1960s, straight out of university in Buenos Aires, he and some friends set up the Estudio de Arquitectura. Within a year they were building office blocks and apartment towers, becoming the most prolific firm in South America. This, he says, “made me grow up fast”. That and Argentina's tumultuous politics. He was working in a university studio in 1966 during a military coup: “The guy next to me just fell to the floor. He was shot in the ass, paralysed for life.”

He carried on successfully for another decade - hitting a career peak with the 1978 World Cup stadium in Argentina - before the obvious realisation dawned that he was working for a right-wing dictatorship. “One day on this building site this guy lands with his helicopter and asks to see the job. I say: ‘You can't, it's a building site.' He says: ‘I have a general with me. Make provisions for this man to walk in here in half an hour or we kill you.' We were always afraid of the police, but not with a machinegun this big.”

A fortnight later the police raided his home: “They took a Larousse dictionary. These guys took it to mean Russia. Thing is, I had Engels and Das Kapital and they left those!” He laughs. “I thought: ‘I'm in the wrong place.'”

He moved his family to New York and never looked back. For every high-profile design such as Tokyo's lauded International Forum, which made his name in the 1990s, or the Manhattan cool club Bungalow 8, his firm has built a stack of bread-and-butter academic buildings, offices, convention centres, medical centres and hospitals. He's a born businessman. “When you've gone through years of 3,000 per cent inflation you develop a character of resilience. This is a lousy profession. People think it's glamorous, but it has a way of shedding the excesses very quickly and very brutally.”

Such pragmatism might have made him better at coping with the shenanigans at Ground Zero - his scheme was just pipped by Daniel Libeskind's. “I have secret feelings of revenge,” he says. “It was truly the wrong scheme, because it was a melodramatic version of real estate, a big visual statement when you don't f***ing know how real estate works. That's mostly the fault of the architect.

“The trouble is people have for too long equated architecture to art. Art is something different. Architecture is something different. Music is something different. They have their own logic. People who confuse them...” He trails off in exasperation.

He had a choice when he was 18, to become an architect like his mother or a virtuoso musician, following his father, who ran the Montevideo opera house. “I was scared of music. I turned my back on it for 20 years.” Now when he can he plays to escape. He owns several pianos, and built a private concert hall at his estate in the Hamptons. “Music is such a different thing. It's completely animalistic. You become elated from time to time but mostly you're confronted by your own inability.”

Architecture, by comparison, “is a piece of cake, a game”. Was it the right choice then? “I'm good at music, but never great.” And at architecture? He pauses. “I work hard.”

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