"We've seen a cross-pollination of womenswear and menswear for some time," Hewson says. "Many of our female customers don't think twice about shopping the menswear floor. Increasingly, we see men buying women's ready-to-wear and accessories too. International brands and designers are showing menswear and womenswear together, or menswear pieces on women and vice versa," she says.

"The energy and attitude of the younger London designers, in particular, is all about being part of a community and nothing to do with traditional ideas of gender."

In some ways, fashion fluidity can be traced all the way back to the culture wars of the 1960s and '70s, when figures like David Bowie began playing the androgyny card.

"Androgynous actually means it has both male and female characteristics," explains Jo Paoletti, an associate professor at the University of Maryland and author of a new book, Sex and Unisex: Fashion, Feminism, and the Sexual Revolution.

Bowie became notorious for bodysuits, neckerchiefs, and a Ziggy Stardust style that slid between male and female like a magic-eye picture.

Unisex designs from Inter-Pret.us. Picasa

Androgyny still has its place (think Tilda Swinton), but what is happening now is more accurately understood as a blank slate.

"Let's erase everything," Paoletti says. "Everyone is going to wear the same thing. It's going to be ambiguous. It's not going to be clear whether it's a male or female garment."


Indeed, these kind of neutral designs already exist in your closet: denim jeans and T-shirts.

"It's the body that defines whether it's male or female," Paoletti says.

Inter-Pret.us has a range of unisex clothing. SUPPLIED

Ambiguous fashion

So unisex is not as radical as it might at first sound. Take Rad Hourani, for example, a Canadian artist and filmmaker now based out of Paris. In 2007, Hourani launched his first ready-to-wear unisex line to considerable acclaim. In 2012, he became the only designer ever invited by La Chambre Syndicale to show a unisex haute couture collection at Paris Fashion Week. Hourani's clothes are sleek and flexible – wide crepe scarves and boiled wool trenches, easily transformed through the use of belts or strategic origami folds. Hourani celebrates "neutrality as a defining human trait," his catalogue states, and he advocates "non-conformity as the essence of individualism".

"In his own vision, he is sketching a new, freer way to live."

Nor is Hourani is the only one. Miuccia Prada was recently quoted as advocating the future of ambiguous fashion. Givenchy and Gucci have experimented with gender-neutral clothing. And more than 40 designers contributed pieces to the Selfridges "Agender" store, including Ann Demeulemeester, Comme Des Garcons, Yohji Yamamoto, and Jeremy Scott. Most of these garments wouldn't look out of place on a traditional rack, including knit cardigans, linen shirts, and high-top trainers. If heads turned at all, it would be because of quality rather than the avant-gardism.

Beyond London, unisex fashion can be found circulating the whole globe thanks to the rising wave of internet trade. Closer to home, the New Zealand-based Kowtow ships neutral designs in 100 percent organic fair trade cotton, as well as clothes aimed specifically at men and women. Nicola Fomichetti, the creative director of Diesel, has also launched Nicopanda, offering a Japanese aesthetic he described rather memorably as "Harajuku sportswear."


A tunic dress by Rad Hourani. SUPPLIED

In New York's West Village, not far from major fashion houses, the start-up Inter-Pret.us is adding its own voice to the mix. Designer and chief executive Derek Guillemette spent years as a merchandising director before committing full-time to unisex fashion.

Versatile clothes

"My clothes are unisex because they're versatile," he says. "There's enough design elements that women still find them interesting, but not so many design elements that a guy would be wearing a costume that would make him feel uncomfortable."

For Guillemette, what makes unisex so compelling in 2015 is its emphasis on choice. Traditionally, designers have dictated the demographic of their garments – this is for men, that is for women – but the decision is now being left as an open question.

"You don't have to design for a specific gender," he says. "Just design a garment you love and let the customer choose what's right for them."

Guillemette has taken inspiration from wetsuits and kimonos (both gender-neutral), and offers smart poplin shirts and coats combining wool and neoprene elements. To get around the problem of sizing a unisex garment, he even created a brand new category: Extra-medium.

Of course, the end point of the unisex trend remains anybody's guess. "Agender" closes at the end of April, and many in the industry are watching Selfridges with close attention. If you push boundaries hard enough, "you might have a kind of cultural fatigue," Paoletti says; people might retreat to categories they already know and trust. But then again, you might also produce lasting effects.

"We have never realised a temporary environment of this scale before," explains Hewson of "Agender".

"This is proof of our confidence in the creative and commercial opportunities of the project."