Hilton is unlike almost any other British big-name designer in that he runs no posh studio, has no assistants, not even a secretary. Now in his early forties, he still has the slightly louche air of the design student, complete with unkempt shaggy hair and a floorful of cigarette butts. He operates from a cluttered workshop perched at the top of a rusting external staircase above somebody else's joinery workshop in north London. Here, in conditions that are more Dickensian than high-tech, he sketches out his ideas, and makes models and prototypes. There is a drawing board, a workbench and a table, bits of chairs and scraps of wood and polystyrene piled up in heaps. Computers are conspicuous by their absence.

None the less, computers were as essential in designing Wait as they are in designing a skyscraper or a suspension bridge. Hilton merely used the equipment available at Authentics - a company noted for all sorts of designerly moulded-plastic products, from bins to beakers, but not previously furniture. Sheridan Coakley, head of SCP, helped to launch Hilton's career in the mid-1980s and is launching a more conventionally upmarket new Hilton furniture range, Glide, at Milan this week. He admires Hilton's doggedness and insight, describing him as "an intuitive designer". When it came to mass production, however, he admits that Hilton had to go overseas. "Wait is the kind of thing that British companies just don't do," Coakley says. "The cost of the tooling is high, and you have to amortise the cost over a long production run. It means that I can sell it at £30, but it's probably more important that Habitat stocks it." Habitat, it turns out, had been wanting exclusive rights to the chair, but found that too many other shops were placing orders: it will now wait to see how Wait goes down in the marketplace before maybe ordering a specially customised version.

Hilton, back in his ramshackle workshop, picks up a prototype of the chair, turns it over, points out exactly how the various moulded strengthening ribs work, describes how the translucent versions are slightly more flexible than the solid-colour versions, and how he worked for two years to get it right. "It's not about making a screaming, shouting design statement," he observes. "I wanted it to be a quiet object. I wanted it to be rational. It can't be a fashion thing - they've got to be making chairs for 10 years."

In the design business, Hilton is seen as a bit of a loner, an introspective type. Wait, for all its importance, is but one of a stream of mostly understated designs from his workshop. His products tend to be slow-burn successes, building up sales over time. When he was designing high-value, low-volume pieces, this meant that riches eluded him. But now Hilton is into the commercial mainstream, that is likely to change. He's understandably chipper about the prospect. He expects to see Wait in people's bathrooms as well as outside in the garden, in cafes as much as on the terraces. He may well have managed to bridge the yawning chasm between popular taste and the culture of high design. In which case, it will come as no surprise to find him designing things other than furniture in future.