Wide boys: Kris Van Assche's Dior Homme collection features trousers as baggy as his predecessor's were skinny

"Of course they are hard to wear," says the designer Kris Van Assche, on the voluminous trousers in his debut collection for Dior Homme shown in July last year. "But then, at the beginning, everybody thought that stretch black jeans were hard to wear." Now, thanks to the legacy of Van Assche's predecessor, Hedi Slimane, the slim silhouette dominates menswear, from mod-inspired suits to the ubiquitous skinny jeans.

Of course, the baggy trousers from this season's collection aren't an innovation, but after years of skinny trousers defying their sell- by-date, they look fresh, and even rather radical. Worn with a crisp, fitted white shirt, they recall David Bowie in his Thin White Duke incarnation, which in turn was influenced by the zoot suit, with its sense of counter-cultural cool. Consisting of a jacket with wide lapels and broad shoulders, and extremely wide trousers, with a narrow cuff at the ankle, the zoot was popular among young black and Hispanic men in America in the early 1940s, as well as performers such as Dizzy Gillespie and Cab Calloway, who famously wore one in the 1943 film Stormy Weather. Like Christian Dior's New Look, which met with protests in London and Paris, the suit incited anger in wartime America, because the quantities of fabric it took to make contravened rationing regulations.

"There was a bit of the zoot suit in there," says Van Assche, "and we went back to the Forties and Fifties, of course."

When he was named as the new designer at Dior Homme, in April 2007, the Belgian designer, now 32, made a decision: "I wasn't going to lose myself in huge concepts and stories. I wanted to reinterpret a classic wardrobe, and look at the heritage of Monsieur Dior."

For Van Assche, that heritage, and the house's USP, is the level of detailing and couture-like finishing that the atelier can provide. "The rule that we have to play by in a big couture house is to reinvent luxury in a fresh way," he explains. "If we don't do that, then there is no reason for us to be around."

Van Assche made full use of the atelier's skills to make the wide trousers pictured here. Despite the fact that they took seven metres of fabric, the designer says: "I don't think of them as baggy trousers, I see them as pleated. For me, pleated trousers are a classic of the male wardrobe, but I wanted to see how I could work with the atelier to really push them from something old-fashioned into something that can be both elegant and modern."

For his first collection, Van Assche decided to host a static presentation rather than a full catwalk show, as it was closer to what Christian Dior used to do, and enables the audience to see the quality of the fabric, and the attention to detail close up. Displayed by models posing against a backdrop of chandeliers, gilt mirrors and stepladders, these included the bias-cut technique on which the pleated trousers are based, and motifs taken from the sewing instructions used in the atelier.

Shirts came with variations on bib fronts and wing collars, while suits included satin tuxedo inserts next to the arms instead of on the lapels. Other trouser shapes he featured were cropped and drainpipe, and also wide-legged, evoking 1920s Oxford bags.

Van Assche regularly includes wide trousers in the signature collection that he continues to design, but his use of a baggy silhouette at the opposite extreme from Slimane's trademark could be seen as a statement of his independence from his predecessor. The two worked together when Van Assche was a design assistant at Dior Homme, and before Slimane's somewhat mysterious departure from the label in March 2007, reportedly over contractual disagreements concerning the designer starting his own label.

Slimane was menswear's biggest star at that time, synonymous with the skinny, rock'n'roll look that spread across menswear, and that Karl Lagerfeld famously dieted to fit into. Taking over from him must have been a daunting affair. "What can I say? Of course I was afraid," admits Van Assche. "Claiming anything else would be ridiculous and pathetic."

He describes Slimane's long shadow as, "like having a really famous father. You know, you try to grow up but people won't let you. I mean, there is no way you can make people forget about Hedi."

Instead of dwelling on Slimane's contribution to fashion, he just embraced the amazing chance he had of working in an atelier "where you can push fashion forward in a beautiful way, with a lot of tradition going on".

Another of Slimane's signatures was the young, thin male models he cast for his catwalk shows, and that have since caught on everywhere, from other menswear designers' catwalks down. However, Assche says, "I don't like this idea of boys who look about 14 representing menswear, who have round shoulders and look at their shoes. It's not reality. The models I used in my first collection are older than many of the boys you see on the catwalks."

The designer casts many of his models exclusively for Dior in South America, and he also finds much of his inspiration there, "in books and in the streets". When he first went to Buenos Aires, he felt awkward, and couldn't work out why, but then realised that it was because people look each other straight in the eye, he says. "I am very nostalgic about it. In Europe, people look at their feet, it's as if we agreed at some point that we would become embarrassed by beauty."

Not so Van Assche, however, who is unapologetic about his pursuit of just that (he has even worked on an art exhibition called Handsome). While at the Royal Academy of Fine Arts in Antwerp, where he studied fashion design in the mid-Nineties, he says that he didn't really fit in with the prevailing aesthetic at the time, or "understand why I would bother to try to make people look bad. All at once, you had to be really clean and cold to have credibility, and all the boutiques started to look like dentists' surgeries."

For his part, Kris Van Assche says that his aesthetic, then as now, has always been "about elegance, but in a fresh, new way".