Once upon a time, before postmodernism came along and muddied everything, being modern was easy. You bought yourself the newest car and zoomed around the country lanes like Mr Toad. You flew aeroplanes. You were new. You were excited.

Jean Prouvé, the great designer celebrated at the Design Museum’s new exhibition, was all that. There is a sepia-tinted photograph of him somewhere, aged 25, from 1926, with a dapper ’tache and thick wavy hair and seated at the wheel of his high-tech Citroën, thundering past the French hedgerows. You might mistake him for an aesthete or a toff. He was neither. From a family of artisans, he had just experienced his first wodge of hard-earned cash. And what does a very modern twentysomething do with his hard-earned cash? He buys a fast car.

Prouvé was the most modern of Modernists. The man was in love with the machine, but not in the romantic, intellectual way of the Italian Futurists – he didn’t have sky-high visions of fantastical, unattainable sci-fi cities with people flying round in jet-pods. “One should not sketch out Utopian projects,” he said, “because evolution can only result from practical experience.” He was a hands-on kind of guy. He simply had “the urge to forge steel, to shape and adjust it . . . to simply make things run”.

Prouvé was born to it. He grew up in Nancy, for centuries France’s capital of craft, furniture and, increasingly in the early 20th century, the steel industry. He was surrounded by the pungent smell of the smithy. His immediate family, though, were artists, albeit of a practical sort. His grandfather decorated faïence pottery, and his father Victor, an artist, was co-founder of the School of Nancy – a band of progressive artists, artisans and manufacturers eager, like Britain’s Arts and Crafts movement, to close the gaps between thinking and making, tradition and modernity, man and the machine.

By the age of 10, the young Prouvé was at home in the workshop, indulging, he said, his “passion for machinery, which, even then, drove me to build things”. He dreamt of being an engineer, but the privations of the First World War limited his ambitions to supplementing the family income at the blacksmith’s forge. By 23, though, he’d opened his own workshop in Nancy, backed by a family friend, making lamps, gates, ironmongery with an Art Nouveau bent, but increasingly experimenting with new Modernist forms and materials, such as stainless steel. It’s proof of his ambition that in 1927, aged 26, he summoned the courage to arrive without an appointment at the office of one of tyhe grandest Modernist architects in Paris, Robert Mallet-Stevens, to show his portfolio of work. It’s proof of his talent that ten minutes later he had a job – making the geometric, veil-like entrance gates for the latest of Mallet-Stevens’s Modernist villas.

And with that, Prouvé was off. The demand for newly fashionable Modernist shapes at home, right down to the doorknobs, meant that by 1930 his Nancy workshop was employing 30 people. His work with Mallet-Stevens and his passion for simple, rational, functional forms gained him automatic entry into the Parisian avant garde. That same year, he co-founded the French equivalent to the Bauhaus, the Union des Artistes Modernes with Le Corbusier, Charlotte Perriand, Mallet-Stevens, and others. Its aim was to unite art, craft and mass industrial production.

But he stood apart from these illustrious colleagues. Perhaps it was his class, this self-taught artisan’s lack of “qualifications”. Or perhaps it was his homespun simplicity, his very unGallic, almost British pragmatism. Le Corbusier’s theorising wasn’t for him. Monuments and glory were not for him. Not that he was unidealistic, but for Prouvé it was simple: Modernism was about helping people, and the machine – mass production – was the rational means to do this by finally fulfilling the dream that had eluded the Arts and Crafts movement: creating beautiful, mass-produced objects, not just for the beau monde but for hoi polloi like him.

You can read Prouvé’s blunt matter-of-factness in his designs. Honesty was one of Modernism’s key themes – that an object should not be draped in style like a body covered in clothes, but should so marry form and function that, like a well-toned human body, you can read its structure through its form. Prouvé was the most honest of the lot. He abhorred fakery, fashion and form for form’s sake. His designs display exactly how they are made, right down to ruggedly flashing their nuts and bolts.

For his products – such as the furniture created for student digs at the Cité Universitaire in Nancy – he worked out, scientifically, in his workshop, how to marry the function with the most appropriate material, in the simplest, most economical form, and the easiest to mass-produce. His talent, though, was in doing this while staying just the right, elegant side of utilitarian. His Cité armchair may be made from just four robust elements, yet in silhouette it resembles, perhaps, four minimalist brushstrokes, like Japanese calligraphy.

Prouvé, though, longed to get his hands on buildings. The medieval nature of the building industry astonished him. He asked the question that has since plagued Modernist architects: why can’t buildings be prefabricated – mass-produced like cars, chairs and aircraft? All it required was breaking down a building into its constituent parts, refining these so that they could be mass-produced, then assembling them.

Eighty years before, in the aftermath of that prefab cathedral – the Crystal Palace in London – Europe, and Britain in particular, was awash with companies churning out factory-made churches, railway stations, hospitals, even villas “in every style of architecture”, as the advertisements put it. Why not again? Prouvé tried it out first in 1935, with the Aéroclub Roland Garros, near Versailles, a simple pavilion, dissected down to its factory-made parts – from the massive supporting ribs stiffening the roof and walls, through the wall panels, down to the lavatories. The design was enlarged and refined later that year in what is regarded as Prouvé’s finest hour: the Maison du Peuple in Clichy, an elegant civic-hall-cum-market-hall of prefabricated parts, held up by a skeletal frame, housing a columnless interior. Other Modernist architects, such as Le Corbusier, had dreamt of creating a machine for living in. Prouvé, though, went out and did it.

He carried on refining his designs right up to his death in 1984, applying them to ever wider contexts – schools, barracks, emergency relief houses, right up to huge exhibition halls, factories and office blocks – reaching his apogee, perhaps, with his maisons tropicalesin 1949 – easy and quick-to-assemble kit homes for Niger and the Congo, one of which is being reassembed in front of the Design Museum. But he never bettered these early experiments in creating prefabricated, lightweight, socially engaged buildings, and, most important of all, establishing the factories with the quality control to mass-produce them. The truth is, we’ve still never bettered them.

Along the way this Frenchman may have given birth to Britain’s only great contribution to 20th-century architectural history – the skeletal, high-tech buildings of Richard Rogers, Norman Foster, Nicholas Grimshaw et al– when as a member of the jury he gave Rogers his break by choosing his and Renzo Piano’s design for the Pompidou Centre. But even Foster’s and Rogers’s Prouvé-inspired dreams of mass-produced elegance for all is as distant today as it was a century ago. His utilitarian furniture has become exactly what he abhorred – fashionable, selling for tens, if not hundreds, of thousands in auction houses; in June one of his maisons tropicaleswas sold for $5 million to the high-class boutique hotelier André Balazs. I think we can safely assume that Prouvé was turning in his grave.

Jean Prouvé is at the Design Museum, Shad Thames, London SE1, from Friday, until March 25 (0870 8339955; www.designmuseum.org)

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