However, the business end of Koolhaas - his Office of Metropolitan Architecture - is a different proposition. He inconveniently breaks a rule I rather cherish- that architects who spout nonsense produce nonsensical architecture, and that those who say and write the least design the best - by being an architect of extreme virtuosity. Koolhaas questions everything. He rejects conventional notions of beauty. He likes the look of the seemingly impossible. Working symbiotically with one of the great structural engineers of modern times, Cecil Balmond of Arup, he does things that have you rubbing your eyes with wonderment.

He has nearly completed one of the world's oddest public libraries in Seattle: try to imagine a kind of angular baseball cap made out of steel mesh. It's a building that glories in its strangeness. He has recently finished the Dutch embassy in Berlin, a smoother, more polite building which contains one of Koolhaas's favoured leitmotifs - conventional floors are broken up, with a continuous ramp spiraling through the space thus released. And a few years back he built a villa for a wheelchair-bound wealthy client in Bordeaux which not only appears to hover in the air, but also does away with the floors thing by having a central room in the form of a lift, rising and falling through the building.