Design: Industrial strength

The Paris-based boss of Kenzo and his sculptor wife welcome Charlotte Philby into the factory building they call home into the factory building they call home

(Photograph by Xavier Bejot)

It is a hazy Monday morning in a northern district of Paris, and a grocer quietly shuffles boxes of vegetables though a low wooden doorway. Metres from his shop, on a side street not far from Stalingrad metro, there stands a disproportionately large green gate. Behind this, concealed by a further set of doors, looms a towering former thread factory: a vast industrial structure running either side of a high, glass-roofed courtyard. The space is now divided into four three-storey apartments; one of which belongs to the CEO of the fashion and design house, Kenzo. James Greenfield and his sculptor wife, Karine, have spent the past decade transforming their flat from a drab concrete construction into a magnificent family home, in which to raise their two young sons.

"We were drawn to the idea of a property with a rich past," Greenfield says, looking up from the cherry wood cabinet from which he is fetching coffee cups. "We loved the idea of a space that had been built for a purpose, somewhere with a past, where we could harness the original features, not override them." His words are muffled by a crescendo of Mozart, bursting from man-sized speakers situated in the corner of the kitchen-cum-living area. Above him, vast cylindrical skylights stretch across the length of a concrete ceiling. "In order to build on what we had," he continues, "we hired the man who had first reconfigured the external parts of the building when it was converted into flats 10 years ago". The man to whom he refers was a Portuguese artisan by the name of Olivier Fossio. He arrived on the first day of business with a broken pencil and a scrap of paper; and having noted the measurements, soon returned armed with a huge sheet of fabricated metal. Fossio's first job was to fashion a concrete staircase, leading from the ground floor to the basement, where Greenfield's sons – Louis, six, and Elliott, three – share a bedroom, adjoining nursery and bathroom.

Working closely with the metal-worker on the design aspect, Greenfield stressed the importance of form and volume. He was keen that the external area delivered space, so rather than separating their home from the outside with a wall, they created a glass façade overlooking the courtyard. With little experience in architectural design, this was an ambitious project for the 40-year-old executive, but Greenfield is not one to pick the easy route. Of Milanese descent, Greenfield was born and raised in the US. His journey to Paris was a considered meander: after taking a degree in political science at Sarah Lawrence University in New York (while also studying for separate courses at the Fashion Institute of Technology), he moved to Milan, where he worked for an American design company for several years. Fashion, he explains, was a way to "be international", and with this in mind he relocated to Paris in 1994 to oversee the revamp of the French department store, Printemps.

Greenfield and his wife were living in the Marais area of the city when they set their sights on the kind of large home that tends to be hard to come by in central Paris. They were resigned to relocating to the suburbs, but when this opportunity arose, they seized it, after a covert stake-out operation. "We needed to ensure that this area was now a safe place to live, so we spent the night scoping the streets from a parked car." Historically, he confirms, this part of the city was associated with "the perils of vagabondage". But now, the nearby canal system is thriving and the close proximity to both the affluent Villette neighbourhood and the trendy Bastille area makes this a highly enviable location.

And the apartment is not bad, either. The front door leads straight into the first living area, where the eye is pleasantly assaulted by a stretch of sky-blue Brunswick & Sons fabric depicting pink flowers and white parakeets. "It's the only wallpaper in the house. And look, we papered over the door too! I've always dreamt of a door covered in wallpaper." Above a central marble table, hangs a cluster of light-bulbs: "our industrial chandelier".

Entering Greenfield's bedroom is like embarking on a 30-second trek across the continents: Mexican tapestry; African figurines; Chinese prints; Russian dolls. And no post-war decade is left unrepresented, from the 1950s Poulin desk to high-tech Japanese wall stencils. "It's about mixing traditions and periods." And there is nothing traditional about the top floor, either. Reached by a winding concrete stairwell, industrial materials dominate the frame of the kitchen/dining area. The robust effect is softened by furnishings and detail: untreated steel windows met by ornate wall-hangings, stone floors lifted with bright Moroccan rugs. And there is one more surprise in store. Above an irregular floral sofa, hangs a seemingly innocuous monochrome image, by the Chinese artist Tsang. As I walk towards it, Greenfield tries to suppress his glee. "Read it," he motions. And as I do, a desperate monologue unwinds: the words "democracy; love; for nothing" all emerge, with a four-letter prefix that needn't be repeated in print. As I turn back towards him, Greenfield can no longer control his delight. "I'm sorry," he says, in his soft feline drawl. "I deceived you, when I said we only used wallpaper once in the house. There are two. Only this one, in my defence, is different because it's framed."

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