If you thought fashion shopping was all about clothes, you haven't visited the latest crop of chic outlets currently opening in London's West End. Marcus Field visits the new boutiques of three leading designers and discovers that, these days, the architecture is scarcely less important - or exotic - than the garments
IMAGINE YOU'RE shopping for clothes. Not just any old clothes, but clothes with labels, big labels: McQueen, Miyake, Dolce & Gabbana. They must be conceptually challenging, exquisitely cut, expensive. Now where do you go? Selfridges, Liberty or Harvey Nicks? Not if you take your fashion seriously.

If you want the full experience, you have to go to the designers' own boutiques, where the environments are created specifically to reflect the brand. Three newly opened London shops illustrate how architect-designed spaces have become a crucial tool in the competition for customers.

For Alexander McQueen's first London store, the cliched solution of a neutral interior would be at odds with the eccentric and flamboyant nature of his work. "I wanted a shop that was interactive, with robots and stuff," says McQueen, "so that people would learn something about the person behind the clothes." He commissioned the architects Ferhan Azman and Joyce Owens to design the store, which is just one of a whole crop of new fashion emporiums which have recently opened on Conduit Street.

If you think it just looks like a smart shop, you would be missing the subtle devices that tell people in the know that it is just so much more. As Azman says, "this is a luxury shop, not Kookai". The messages are in the house-of-fun elements like the glass changing-room door which is clear before you go in, but automatically turns opaque when it senses your movement. Then there's the big glass vitrine at the entrance which can be filled with seasonal displays (it currently contains a snowstorm) and sticks out into the street. McQueen would have liked it to project further, "as a bit of surrealism", but Westminster planners weren't having any of it.

Back inside, the architects have devised a display system in stainless steel rods which looks like a giant piece of gym equipment. There are mechanical bits so clothes can revolve and big metal frames in which garments can be pinned out like dead butterflies. The point is to put the clothes in some kind of context, so that customers feel they're getting the McQueen experience, whether they're spending pounds 60 on jeans or pounds 8,000 on a beaded coat. The music is hand-picked too. Ideally, McQueen says, he would play only Diana Ross, but he thinks the staff might get bored.

Issey Miyake is known for his challenging designs (in his latest range, you buy a strip of cloth and cut out the clothes yourself), so for his new store - also on Conduit Street - he naturally wanted a space which would reflect his experimental approach. Miyake's choice of architect is Stanton Williams, a team known for its classy exhibition designs at places like the Hayward Gallery and the Royal Academy. But Miyake didn't want his clothes to be shown like art. They're not precious, he says. He wants you to come in and try them on. To convey this message, the architects have created enormous windows which give passers-by a view right in. And unlike the chi-chi Prada and Gucci stores on nearby Bond Street, there will be no black-clad doorman or fiercesome sales assistants.

Inside, what look like plain white walls are actually meticulously finished in plaster mixed with ground marble. The pale-grey concrete floor has been polished to the high shine of wood, and the staircase is constructed of toughened glass. The only colour, says the architect Paul Williams, will come from the reflection of the clothes on the walls. Miyake's famously sculptural garments in impossible-sounding acrylics hang on a stainless-steel rail in the centre of the space. It's no ordinary rail though, but part of an architect- designed system which can be reconfigured in numerous ways. "Everything," says Williams, "is custom- made." The only element of decor-ation in the store is a 12-metre-long ceiling installation by Ingo Maurer, a Swiss artist and designer with a reputation for making structures that are as clever and witty as Miyake's clothes.

Just round the corner on Old Bond Street is the newly opened Dolce & Gabbana flagship store. The big windows along the street are filled with impossibly short skirts, fitted suits and tight glittering tops for both men and women. Sexy and glamorous is how the designers describe them. Clothes for rich people (beaded coat, pounds 23,000) who want to dress up like hookers and gigolos would be an alternative view.

"Every fashion shop looks the same," says the architect David Chipperfield wearily, as he explains the starting point for the store design. "The only thing you can do is go back to the clothes, so that you're not competing on interiors. You should avoid long rails, make the shop full, and have no glass shelves. The interior design cannot replace the content."

Chipperfield is an old hand at fashion shops, with past clients including Miyake, Esprit and Katharine Hamnett. His established style is to keep things simple, so at Dolce & Gabbana the big idea has been to line the floors and monumental staircase with black volcanic stone, and let the clothes do the rest. The nuances, which might pass most people by, are in the finely crafted teak display system and glass screens. These might look tinted, but the panels are actually sandwiched together evocatively around a layer of Sicilian black silk.

Chipperfield would be content to leave it at that, but Dolce & Gabbana, being Dolce & Gabbana, have added a few props. So there's swooshing red velvet curtains in the changing rooms, and big baroque thrones on the shop floor. All of which is enough to make you feel like you've walked into the setting for a Caravaggio. Now you wouldn't get that at Selfridges, would you?