Timeless style – updated: Yves Saint Laurent

The turtleneck, the tailoring, the tulip skirt... it's all classic Yves Saint Laurent – but with a twist. Creative director Stefano Pilati tells Susannah Frankel why nothing in fashion should stay the same. Not for long, at least

'Iwas thinking about power, and about a powerful woman," says the Yves Saint Laurent designer Stefano Pilati. "But not a powerful woman in the sense that she is a CEO or anything like that. Instead, this woman is powerful with confidence, with experience, dressed well but, at the same time, quite cool."

If anything exemplifies the look that Vogue recently described as "the new austere", and, indeed, the suitably modern take on power-dressing that appears to go hand in hand with that, it must surely be the autumn/winter collection courtesy of this, perhaps the most iconic of French brands. All the time-honoured signatures are in place: the black turtleneck that Yves Saint Laurent himself famously sent out on to the haute- couture catwalk as part of his seminal 1960 Beat collection inspired by Parisian street style; the tailoring borrowed from menswear but adapted to suit the feminine form; the classic tulip skirt; and the colour co-ordination touching everything from accessories to models' lipstick – in this instance, all are black.

The experimentation with volume seen throughout the collection – either subtle or overt – is what makes it seem fresh, however, and also gives it a sense of understated luxury. "The volumes for me are what define the difference between high- end and low-end fashion," Pilati explains. "The clothes may be quite simple on one level – it's not like haute couture, there's no embroidery, they are what they are – but there's no point whatsoever going to a store such as Zara, for example, to find these clothes. The time and the research that has gone into making the patterns are what makes them appealing."

The volumes in question, Pilati elaborates, are inspired – and this seems, on the face of it, more surprising – by sport. "Yes, I was thinking about sport in the sense of general inspiration and as it relates to mental attitude, about the performance of the fabric, how you treat the curves in the pattern, but also about the idea of people having to perform constantly. I used Donegal tweed, felt, cashmere, often unlined. Clothes were either very fitted or large. For a few seasons now, I have attempted to go back to the essence of clothes, to think about what they really mean. I want there to be a sense of functionality and even utility to the collections."

When, two years ago now, Pilati came up with a collection that was comparatively masculine, oversized and almost entirely grey, it represented something of a departure for the Yves Saint Laurent look. Until that point, a basically bourgeois, fitted, hourglass silhouette, embellished with classic couture staples, from gold braid to jewelled encrustations, waterfall ruffles and frills, had been the order of the day at this label. The Italian-born Pilati understood it well, and for that reason his creations were embraced by everyone, from the more mature Saint Laurent customer who had invested in the name when its eponymous founder was still at the helm, to a younger, more obviously fashion-conscious consumer for whom there was a certain irony to wearing the sort of clothes that her mother and even grandmother would adore.

The restless energy that characterises any great designer was, in Pilati, very much in evidence, however, and so, having perfected this particular style, Pilati moved on. The severity and comparative minimalism of his approach from then on was seen at the time as quite radical – and even risky. Elsewhere, fashion was, at that point, still dominated by clothes that looked as obviously expensive as their price tags indicated.

This is how the designer himself describes this development. "When I first took over at Yves Saint Laurent, I was testing the imagery, trying to find out what Saint Laurent meant to people, everybody had an opinion. The only pushing I did was gentle. Once I was confident that I understood certain basic codes, I moved more towards experimentation. I started to find my own way."

It is worth noting, however, that any innovation aside, the effortless elegance for which the Yves Saint Laurent name is known remains proudly in place. What's more, by now, the rest of the world has caught up with this designer. In his hands, Yves Saint Laurent is today recognised as one of the more pioneering names in Parisian fashion, one that moves things forward as opposed to being overly reliant on past glories, all be they considerable.

This season, the Yves Saint Laurent look appears more appropriate than ever. There is little place for frivolity or ostentatious self-adornment just now, after all. Instead, a sombre colour palette, a covered-up silhouette, and a return to what may perhaps best be described as a "working wardrobe" is de rigueur, and nobody does that better or more imaginatively just now than this particular designer.

More importantly, Yves Saint Laurent collections are evolutionary rather than revolutionary: they develop seasonally, as opposed to introducing a grand new idea every six months, and then throwing it out for yet another ideathe next.

"I'm building the house, the history, the heritage, the continuity," says Pilati. "I am aware of the huge amount of choice there is in fashion, and I think that may be confusing. If you are a fashion designer, you need to make the effort to be quite identifiable in a very precise, simple way. Pushing people to buy, buy, buy just because they think they need to, or, more significantly, because we need them to, and seducing them with ephemeral codes is not right."

Brave words indeed, particularly coming from such a high-profile fashion talent. Above all, though, Pilati says, this collection represents a subtle view of female sexuality over and above an overt one, an aesthetic that is suggestive as opposed to plain obvious, which seems entirely relevant for now.

Pilati's reasoning is at least partly pragmatic. "We are talking about a winter collection here," he says, laughing. "And I think it is important for there to be something to discover about a woman, for a look to be not too in-your-face."