That notion has shifted a lot. In the heart of Whitehall, a new Coates temporary building is being assembled to house "Powerhouse UK", a £1m exhibition of British creativity. And when the Ideal Home show opens next week, there among the ghastly spec homes and caravans will be his "Oyster House", which may have its flaws, but succeeds in being unlike any other house you have ever seen.

Until recently, if you were asked to name two national institutions that Coates was unlikely ever to work for, they would be these: the British government, and the Ideal Home exhibition. How could he? Coates was seen as radical, dangerous. Worse, he was difficult to pin down – his exuberant "narrative architecture" played no part in the style wars of the 1980s. He became known for fashionable and ephemeral bars, restaurants and shops, particularly in Japan, and lately some well-regarded exhibitions back home, including the Royal Academy’s very popular Living Bridges show, and the Design Museum’s equally crowd-pulling Erotic Design. He was made professor of architecture at the Royal College of Art. But all these things did not add up to official patronage. Nigel was still seen as a bit of a naughty boy. Since when, something has changed in Britain’s attitude to him.

As well as Powerhouse and Oyster House, Coates is to design Britain’s national exhibition at Expo’98 in Lisbon, starting this May. He has even managed to get a toehold inside the Millennium Dome at Greenwich, where he will work on the already famous "Body Zone" with its giant human figures. His design approach, it seems, is just the ticket for Cool Britannia. Not for nothing was he a guest at one of the very first Tony Blair Downing Street soirees: Blair will open Powerhouse UK to European leaders at the start of April. As well as all this, Coates’s National Centre for Popular Music in Sheffield, and his Geffrye Museum extension in East London, are nearly complete. As his architect partner, Doug Branson, puts it: "For so long we were out in the cold – now we’re being engulfed with work." The firm of Branson Coates is duly bursting out of the Clerkenwell studio it has inhabited so easily for years.

Powerhouse UK is a direct response by the Department of Trade and Industry to last summer’s report by the think tank Demos, "BritainTM: [m2(TM for trade mark)[m0Renewing our identity". The report, which found a willing audience in the new government, put forward the idea of Britain as a "creative island" in fashion, music, drama, architecture, design, films, advertising, science, medicine – even computer games. Coates was one of those consulted for the report. Powerhouse UK is an exhibition of exactly these things.