Alexander Wang: Too cool for school

While some designers look to the past or future, Alexander Wang is as right here, right now as it gets. The American designer is zeitgeisty, he's of the moment and in fashion-speak he's also having a moment; quite an extended one to judge by his growing popularity.

Wang's aesthetic has a metropolitan immediacy to it, a throw-it-on, wear-it-now look that caters to the urgency of his New York customers and reflects the rushed style of models between shows. Typically, it was the 25-year-old wunderkind himself who came up with the expression that sums up both his signature and the urban uniform of the late noughties; the "model off-duty" look synonymous with skinny jeans, long T-shirts, biker jackets and ankle boots. When I meet Wang at his new space on Selfridges' 3rd Central floor – his first dedicated area in Europe – which is complete with metal and shaggy wool chairs from his old apartment, the amiable, sweatshirt-clad designer explains what he meant by the term. "It's this very dishevelled look that I was known for from earlier shows," he says, "but it goes deeper than that. I was thinking about how this high-low mix came about, and I felt that it originated from girls backstage." Unlike women who buy just high end or high street clothes, Wang evokes, "a model who runs around in jeans, but then she's introduced to Karl Lagerfeld and he gives her a Chanel jacket that she throws on. It's this idea that everything is the same, treated in a very equal way without rules."

It didn't exactly hurt Wang's dizzyingly fast trajectory from leaving his degree at Parsons The New School for Design two years early to becoming a highlight of New York Fashion Week, (Roisin Murphy, Diane von Furstenberg, Philip Green, SJP and Anna Wintour were all at his a/w 09 show) that he had an off-duty model on hand to epitomise his customer. Or at least who his customer wants to be. Wang met the Texan model/self-styled free spirit Erin Wasson when she moved into his old building two years ago. He says: "It was my first show, the clothes were there and she was trying them on and I was like, you should help me style the collection, so we did that for two seasons. Working together was really fun. She doesn't still do my styling but she is a good close friend."

Wasson's breezy, "like whatever" vibe helped confirm that Wang was cool, and that elusive quality rapidly translated into credibility and commercial success. Wang, his brother, who previously had a legal career, and his sister-in-law, officially started the family business in late 2004 and have no outside investors. A small knitwear line came out in early 2005 and the family "put it in a suitcase and took it door to door trying to spread the word". However, it was in 2007 when they launched the ready-to-wear line that Wang, "really felt like the brand came together with the idea of our girl and what we are trying to say". Since then the label has grown to include shoes, accessories, handbags, a T-shirt line, menswear, and sunglasses, and Wang has also collaborated with Uniqlo and Gap.

Wang might be very young for such success, but he was clearly ambitious, independent and focused on fashion from a young age. Growing up in San Francisco, with Chinese-American family heritage, he taught himself to sew in his early teens after his mum bought him a sewing machine. He staged his first fashion show aged 15 at his brother's wedding. "It was like 35 looks or something. We hired hair and make-up and everything," he recalls in his New York hipster drawl. He did a course at Central Saint Martins College, "just after 8th grade so I was about 15", and when he finished high school at 18 he moved to New York to study at Parsons for two years before dropping out to start his business. He says: "It wasn't pre-planned. I thought I would attend school and get an assistant position and work my way up but being in NY and seeing the pace of everything, is very inspiring."

In 2008 Wang won a prestigious CFDA/Vogue Fashion Fund Award, and alongside previous winners and runners-up in the scheme such as Proenza Schouler, Phillip Lim, Thakoon, Derek Lam and Rodarte he is seen as one of the fresh new designers putting the energy back into what had become a staid scene at New York Fashion Week. As Selfridges buyer Ros Leach says: "There's no denying Alex has been a key factor in its renaissance." Wang muses: "I don't think fashion week will go back to what it used to be because people are realising that the industry is completely changing. It's not just in Bryant Park any more, people are figuring out who their audience is, where they want to show, they aren't really playing by the rules. It's not so much about these editors, these buyers. These designers. There are a million different stores, and different voices now."

Wang might be part of the new guard of American designers, with an ultra-contemporary look, but he's still inspired by traditional American motifs such as sportswear and the idea of classics. For the spring/summer 2010 show Wang was, "thinking about American heritage and sportswear, parkas, camping, growing up in America, college dorm rooms, that idea of the Bruce Weber girl". Of course with Wang the look came with an ultra-modern, slightly grungy, offbeat, pop culture twist courtesy of the prissy girls in the film Clueless. "I thought, how do we see it differently now, how can we make it relevant now?" he says.

It didn't take the high street long to cotton on to the fact that Wang's brand of relevance or hip wearability is what its customers want now, and a glance around the likes of H&M, Topshop and Zara reveals plenty of Wang-alike long T-shirts, tailored gilets, sleeveless leather or denim jackets and grey tracksuit trousers – as seen in his s/s 09 show. The designer seems fairly unconcerned about the plethora of homages, however, saying: "If someone realises the piece they are wearing is inspired by me then it only broadens my audience."

Anyway, Wang is on mingling terms with one high street titan – Sir Philip Green – they met at a Topshop party in New York. "Very charming, he likes to have a good time" was Wang's verdict. He's also met Anna Wintour ("she's amazing, definitely someone who knows what she wants and she does a great job") but the person he was most thrilled to meet was Kate Moss. "I went with her to Miami for a shoot with Daria Werbowy and Lara Stone and Kate took us out to these dive bars, she was like our tour guide, she's the most down-to-earth fun ever." What time did the night end? "I don't know if it ended, it kept going and going." Rather like Wang's status as New York's hottest young designer.

Alexander Wang is available on the 3rd Central floor, Selfridges London; 0800 123 400