''IT'S called Excessive Sensual Indulgence,'' Isabella Blow said, gleefully cranking up the electronic sequencer that regulates the pulsating fountain-shaped light sculpture in the Vampire Room of her new house in London's Waterloo. By day, nothing about the conventional Georgian facade of the former artisan's cottage Ms. Blow shares with her husband, Detmar Blow, an art dealer, prepares visitors for the blazing modernity of the interior or the eccentricity of its inhabitants. By night, however, passers-by are often startled by the merrily demented light show emanating from the curtainless ground-floor windows, creating the impression that the house is throbbing with pleasure.
''It was originally a hatter's house,'' Ms. Blow said with a note of triumph, as she led a visitor on a tour of the couple's recently renovated home, where rooms are named after the art. Dressed somewhat alarmingly for breakfast in a burnished steel corset, Ms. Blow also sported a silver-disk hat created for her by Philip Treacy, the milliner, to celebrate last month's lunar eclipse.
A blue-blooded renegade, Ms. Blow, 40, is an influential stylist and fashion powerhouse, long celebrated and pilloried for her role as muse to fashion's avant-garde, including Mr. Treacy and Alexander McQueen, who is showing his spring collection today at Pier 94 in New York. Ms. Blow makes a point of wearing the fantastical outfits that critics often praise on the runway but are horrified to see in the street, especially when coupled with a very large hat.
But it is only with the purchase of her London home that Ms. Blow has focused her energies on inspiring young artists and architects to help conjure up a house for the new millennium, complete with a transparent bathtub and a see-through sofa through which movies can be projected. The result is no less outre than her garb, but it is clearly a stimulating playhouse for a woman who is passionate about forging connections between art and fashion.
When speaking of design, Ms. Blow often sounds as if she were declaring a cultural manifesto. ''I think the millennium is about reflections and light,'' she said, adjusting her steel corset. ''And that's what our architects gave us -- modernity and light.''
When the Blows bought their two-up two-down cottage for about $300,000 in 1997, it was woefully decrepit. ''It was dark, dingy, and the basement was flooded,'' Ms. Blow said. ''Someone said, 'All you need is a fishing rod.' '' The unfashionable neighborhood was a far cry from the swank of Belgravia, where the couple were renting, but its advantages were swiftly recognized by the surprisingly practical-minded stylist. ''It's five minutes from the Savoy and 10 minutes away from communion at Westminster Abbey,'' noted Ms. Blow, a devotee of ritual, who worships at an 11th-century private chapel. Furthermore, her office at The Sunday Times of London, where she is the fashion director, ''is only four quid away by taxi.''
To modernize and expand their hovel, the couple engaged Ferhan Azman and Joyce Owens, talented young architects, who added a starkly modern two-story glass extension to the rear of the house to provide a bathroom and a gleaming stainless-steel kitchen. The newly transformed house has just been nominated for an award from the prestigious Royal Institute of British Architects.
''We've been very fortunate to work with Isabella, especially when she has wild ideas,'' said Ms. Owens, who is currently designing a Surrealist-style chandelier for Ms. Blow that will jut horizontally from a wall in the Vampire Room and cascade in crystals to the floor.
''Ferhan and Joyce told me, 'This house is going to be like a piece of couture,' '' Ms. Blow said. ''They asked to see all of my hats and shoes, and they measured them. Detmar asked for a place to keep his cuff links and ties, and said he wanted a house where he could run around naked.'' Practiced at exuding an air of aristocratic nonchalance, the couple seem to extend their artful public exhibitionism to their private life. Drawn blinds in the bedroom preclude curious glances, but much of the house is open to inspection -- a sort of blue-blooded reverse of ''The Truman Show.'' ''I'm a voyeur,'' Ms. Blow said. ''I think everyone in fashion is a voyeur.''
To transform the gloomy basement, Ms. Azman and Ms. Owens came up with the ingenious idea of installing three glass panels in the floor of the two original ground-floor rooms. Now awash with natural light during the day, Ms. Blow's subterranean office is lined along one wall with floor-to-ceiling stainless-steel closets that bespeak a desire for uncompromising efficiency.
When Ms. Blow introduced the architects to Ben Curnow, an artist whose work she had admired, Ms. Owens suggested incorporating one of his sculptures into a glass floor panel in the sparsely furnished living room. Mr. Curnow's sculpture, composed of a water tank and a powerful blue light, creates the mesmerizing effect of waves lapping toward an ever-elusive shore.
''At night, the whole place is blue,'' Ms. Blow said, referring to the living room, hallway, basement and street. ''I think blue is a spiritual color -- it purifies you.''
Climbing the stairs, visitors come face-to-face with five horizontally stacked portraits of Andy Warhol, who befriended Ms. Blow in the mid-1980's during her stint as an assistant to Anna Wintour at Vogue, after noticing that she was wearing one pink shoe and one purple shoe. At the top of the stairs is Ms. Blow's pristine dressing room, for which Ms. Azman and Ms. Owens designed sleek glass-fronted closets to create a gallery-like setting to display hats and shoes from her collection.
''I love that it looks like an accessories shop -- it could be Prada or Gucci,'' Ms. Blow said.
For the bathroom, the architects designed a voyeuristic glass-sided tub and a transparent rear wall. ''We came up with the idea because we thought it would be a bit over the top,'' Ms. Owens said with classic understatement. Ms. Blow, describing the spectacle of her husband enjoying a soak, noted, ''It's like having a little Botero in the bath.''
So what do their friends make of it? ''Having a glass bathtub is one thing, but having a glass-walled bathroom that the neighbors can peer into is pretty wild,'' Mr. Treacy said. ''It's fairly explicit at night, I'm sure.'' (Artfully concealed roller blinds protect their modesty, but the Blows clearly enjoy visitors drawing the same conclusion.)
For Ms. Blow, the house's lean modernity is a welcome antidote to tragedies in her family's past and to the pace of her professional life. ''I want it to be like a hotel you check into with no memories,'' she said.
With its compact size, bright white walls and eye-popping contemporary art, the Blow's London cottage is a striking contrast to Hilles, the majestic Arts and Crafts manor house in Gloucestershire, where they entertain on weekends. Built in 1913 by Mr. Blow's grandfather, a distinguished architect also named Detmar Blow, Hilles is an imposing and somewhat theatrical confection of yellow stone, Tudor portraits, 17th-century furniture, William Morris carpets and Burne-Jones tapestries. Perched on a plateau overlooking the rolling Malvern Hills, it offers a romantic, bird's-eye view of the winding Severn River and of Gloucester Cathedral, where the couple were married with giddy pomp and ceremony in 1989.
''What I love about Hilles is that it's one man's vision,'' Ms. Blow said, leading a visitor on a recent tour. ''Every stone, every hinge, was chosen by him. He designed it top-to-toe, as it were.''
Magnificent at night, the house is decidedly melancholic by day. Mr. Blow's father committed suicide there in 1977, and his heirs seem not to have gotten around to burying his ashes, which sit in an elegant box bearing his name on a desk by the dining table, in front of a gilded 18th-century French clock, which has not been wound since his death.
Escaping the house for a rambling country walk one recent afternoon, Ms. Blow introduced a visitor to a collection of splendidly plumed Japanese chickens lent by the English couturier Anthony Price. ''It's amazing they've got any feathers left,'' Ms. Blow said with calculated astonishment. ''Philip Treacy's always plucking them for hats.''
An inspection of the family's short-tailed Soay sheep in a nearby field prompted further sartorial anecdotes. ''Philip did a hat based on the ram's horn, and Alexander McQueen did the horns in gold for his first collection at Givenchy,'' she said. ''But I've lost my ram -- they die from too much sex, you know.''
Having decided recently to create a new entrance to Hilles, the Blows commissioned Roderick Gradidge, an expert on Arts and Crafts architecture, to design gateposts in Cotswold dry stone, topped with dovecotes. ''It was Detmar's idea, and I think it's so romantic,'' Ms. Blow said. ''When you arrive, you'll have this flutter of doves to welcome you.''
The Blows are legendary hosts, and the visitors' book at Hilles is a veritable Who's Who of Britain's youthful haute bohemia. When Mr. McQueen is in residence, he commandeers the vast Long Room, with its William Morris carpets and a magnificent 17-century Mortlake tapestry. Sophie Dahl and Honor Fraser, models whose careers were begun by Ms. Blow, are also frequent guests, as is Jasper Conran, the London designer, who is currently negotiating with Mr. Blow to occupy a sprawling house on the estate.
Although it is an impressive setting for house parties, Hilles is the antithesis to the Blow's serenely modern cocoon in London. ''It's very overpowering,'' Ms. Blow said. ''It's a bit like living inside a theater set.''
The experience of owning her own house in London has an emotional resonance for Ms. Blow. Her father, Sir Evelyn Delves Broughton, died in 1993, leaving her only about $8,000. Her stepmother, whom Ms. Blow described as ''a creature called Rona who he met on a bus in Hong Kong,'' inherited his country estate, which had been in the family since the 14th century, along with the tidy sum of $11 million. ''I was shocked, because I had loved him,'' Ms. Blow said.
Nevertheless, she seems to relish her role as a madcap chatelaine at Hilles. Some may opt for faded jeans or tweeds in the country, but not Ms. Blow. Wearing a frothy muslin floor-length dress by Yoshiki Hishinuma, Jungle Red lipstick and silver stilettos, Ms. Blow could hardly be mistaken for the housekeeper as she greeted house guests in the kitchen at 8 A.M. and inquired, saucepan in hand, ''Anyone for porridge?''