Making the news An exclusive joint interview with Renzo Piano and Lord Richard Rogers, moments after they successfully conveyed a flock of sheep across the Millennium Bridge

It took weeks to arrange a joint interview with celebrated architects Lord Rogers and Renzo Piano. The two jet-setters are rarely in London at the same time and when they are, they have to search hard to find 10 minutes for the press.

But last Saturday was an exception. The great men, who both appear in our Hall of Fame supplement this week, were in the capital to guide a flock of sheep across the Millennium Bridge to the City of London as part of the London Architecture Biennale, and they agreed to an exclusive joint interview with Building.

Undeterred by the animal rights protesters along the route, and both wearing T-shirts with the reassuring words: "Trust me, I'm an architect" Rogers and Piano negotiated their way along the route. Straight after they delivered their charges, they jumped into a taxi and invited Building along for the ride.

In the hour-long traffic jam from the City to Rogers' office in Hammersmith the two reminisced about their collaborations, most notably on the Pompidou Centre in Paris, and 37-year friendship.

Lord Rogers and Renzo Piano

Lord Rogers and Renzo Piano

Ceremonial shepherds

The symbolism of herding sheep into heart of the capital was not lost on either man. "The right of passage with animals is the history of the transformation of cities over the past eight centuries," observes Piano.

"It's also about civic rights," adds Rogers. "It gives workers and their products the right of entry into the exclusive walled city. And it's something we're fighting about right now with the use of Parliament Square."

Both architects have big projects in London: 68-year-old Piano designed the Shard of Glass, soon to be reaching for the sky above Southwark cathedral, and a commercial scheme near Centre Point. Rogers, 72, is still immersed in Heathrow Terminal 5 and office developments in the City and overlooking Hyde Park.

Piano's practice, Renzo Piano Building Workshop, has 110 staff divided between Genoa and Paris, whereas the Richard Rogers Partnership has 130 staff, mainly in London with outposts in Madrid, Barcelona and Tokyo.

The Pompidou years

It was in London in 1969 that the architects first met, two years before they won the design competition for the Pompidou Centre in Paris. Their initial introduction was nearly snuffed out by - of all things - measles.

"I met this man, Dr Franklin, who invited me to visit Richard with him, as he was going to treat him for measles," said Piano. "And I said, ‘Hey wait a second. How can I come too, if he's got measles?' And he said, ‘Don't worry, come with me.' So we met then, and Richard was talking Italian not English. It only took five or 10 seconds to become friends. And a year later we formed a practice together as we were both teaching at the Central London Polytechnic."

Richard was talking Italian not English. And it only took five or 10 seconds to become friends Renzo piano

Although they agree that the seven years they spent designing and building the Pompidou Centre was the highpoint of their friendship, it has continued since. "We meet up monthly, sometimes more," says Piano. "We're not making any buildings together, but Richard pokes his nose in my business and I poke my nose in his. Every time I see him, it's an enjoyment."

"It's not done in any formal way," says Rogers. "We just walk around the office and talk like we're doing now, and we have good catalysts."

"Normally a glass of wine," chips in Piano. "That's the most pleasant catalyst."

Two men, no dog: Rogers and Piano’s charges hot-foot it from the Tate Modern

Two men, no dog: Rogers and Piano’s charges hot-foot it from the Tate Modern

Family ties

The growing and evolving families of the two architects have also become close. Nudging his second wife sitting next to him, Piano continues: "Milly showed up 18 years ago, and she was immediately adopted by Richard's family. And the whole thing is dispersing too, because we have all visited Richard's son, Roo, who is living in New York. And then we go to Paris where we live with our little boy, Giorgio, who's seven."

"I think this family bonding is pretty Italian," observes Rogers, who is himself of Italian extraction. "But my wife Ruthy, being more from the Jewish side, says it's also Jewish. And it also comes from people who move from another country, because they need to keep in touch with their compatriots."

Both architects are wary of the vogue for empty stylising (see "Piano and Rogers on …"). So how do they guard against that in their own practices? Could it be a matter of maintaining them at a critical size?

For Piano, size does matter. "I feel that about 100 people is right because it's fundamental to designing that you know everybody and know them by name. I spend my time in the office sketching, working and discussing. Rarely do I take time off to do an interview - that's why were doing this one in a taxi cab. This is something Richard has taught me in the past. It's about constant determination and stubbornness."

Well, does such determination and stubbornness leave any time for holidays together? "Yes," says Piano. "My family is going to Greece early next month, and then we'll sail back via Sicily. We're trying to persuade Richard to come, but it probably won't work this time."

And as the two great architects get down to sorting out their holidays, the taxi pulls up.

Piano and Rogers on … the dangers of celebrity architecture

As part of the London Architecture Biennale, Piano gave a sermon last Friday at Southwark cathedral about the struggle in architectural design between practical matters and aesthetic aspirations.

The next day, in the taxi, Piano expressed his concern that architects – and their camp followers – could be seduced by the pursuit of visual impact to the detriment of more practical matters.

“There’s all this mythology about buildings being sculpture. It’s all part of the celebrity thing, which is actually about the celebrity
of architects rather than architecture.

That’s the danger, because it’s revering architecture more as an aesthetic than a social force.

“But architecture must be loved and admired first of all as a social force, and eventually for its beauty and aesthetic value. If you reverse things, it becomes ridiculous.”

The current danger in architectural design, says Piano, is to treat architecture like a fashion accessory. The culprit for this, he says, is computer-aided design.

“You can see so many talents that are spoilt by computers and the facility to reach results without struggle. It’s a bit like those word processors that correct you when you type something in wrongly. It becomes too easy to design a building just like a fashion accessory or a sculpture. What is missing is the struggle and a bit of suffering.”

For Rogers, the problem is that the modern movement has been debased by mindless copying. “For instance, international modernism in the hands of the best, like US architect Skidmore Owings and Merrill, was fantastic, but it became wallpaper, and it had none of the spirit. And Frank Gehry, when he’s on form, does great buildings. But there are very few Franks around, and they are very difficult to learn from.”