Paul and her designer, John Robert Wiltgen, refuse to discuss the price for such luxury, in part because it’s included in a renovation of the entire 1924 house, in part because the chandelier hasn’t even been ordered yet. But in general, an adequate budget for a top-of-the-line master bath runs about $50,000, half of what people might pay for a kitchen of the same quality. Of course the bathroom is usually a much smaller room–although sometimes not, as in the case of a 1,600-square-foot bathroom Wiltgen designed for a couple in Rancho Santa Fe., Calif. It has floor-to-ceiling bookcases, three televisions, two whirlpool tubs, two toilets, a bidet and a steam shower ““for eight of his closest friends.’’ Wiltgen’s profession is the beneficiary of a powerful trend in American society: the estheticization of the everyday, symbolized (this year) by a $246 pair of Baccarat cobalt-blue crystal faucet knobs from Kohler, for the purpose of turning on the water to brush your teeth.

Toothbrushing, to state the obvious, is done the same way in a $1,200 hand-painted sink as it is in anything you might get at Home Depot. The boom in luxury bathroom design is driven by fashion, ego and self-indulgence. No one keeps statistics on high-end jobs, but the National Kitchen and Bath Association says the average cost of bathroom renovations has risen noticeably in the last few years, even in places not otherwise noted for being on the cutting edge of design. Homeowners with substantial budgets, like Paul, might spend thousands on a sink. But even those with more modest means are splurging on heated towel racks or self-adjusting thermostatic shower controls–the best, selling for up to $1,500, claim to keep water temperature constant to within one eighth of a degree.

In contrast to kitchens, bathroom design is not primarily inspired by huge leaps in technology. The age-old problems posed by male anatomy have inspired exactly two inventions. One is the home urinal, which controls splashing, saves water and puts an end to marital discord over where to leave the seat. The other is a toilet with–in place of a lever–a concealed electronic control that flushes when the lid is lowered.

““People want to be coddled,’’ says Alan S. Asarnow of Ridgewood, N.J., an NKBA Certified Bath Designer–he had to pass a daylong exam–and winner of numerous bathroom-design awards. His typical client is a couple with grown children who are taking over a kids’ bedroom to incorporate it into the master bath. ““They want a whirlpool, a large shower, separate lavatory basins. I’m not sure how many of these whirlpools ever get used after the first month, but they all want them.’’ Whirlpools start at $1,200 and can churn past $35,000.

If that seems frivolous, you can spend just as much on something practical, like a shower. ““You wouldn’t believe what people are putting into their showers,’’ says Faye Norton, who distributes luxury bathroom fixtures in Oklahoma and neighboring states. Almost every new shower she sells has an accessory that turns it into a steam bath. Huge shower heads, 18 inches in diameter with 60 jets, are becoming popular. The water falls like spring rain, she says, except rain is free and these cost as much as $7,000, depending on the finish. ““I did one shower for a doctor in a little town here in Oklahoma. We put in one big head, 12 horizontal body sprays, two wall shower heads and a hand shower. He had to have two drains to accommodate the water.''

The other trend in the industry, besides ““coddling,’’ is a level of opulence in design and materials that would have turned heads in Pompeii. Where once obscure industrial designers toiled, now the prominent French architect Philippe Starck designs bathroom fixtures, including a $2,600 toilet. His simple white washbasin, inspired by a 19th-century design, sells for $995, without a base or faucet. So precious are its lines that it is meant to sit atop a counter, like a bowl, and thus be visible both inside and out. This conceit is very chic right now, conveying as it does a refined antiquarian taste, as well as the message ““I have somebody else to clean around the bottom of this thing.''

The watchword in bathroom design today is an eclectic Classicism, bearing in mind that the Classic period for bathroom fixtures was approximately from the 1920s to around 1940. Cast-iron claw-foot tubs are enjoying a revival, notwithstanding that they are enormously expensive and, because they’re free-standing, tend to cool off quickly. Although Starck’s sink is meant to be used with a very sleek single-handled faucet, the vogue now is for the traditional look of two handles, especially a kind of faux-tenement design with four spokes and porcelain inserts that say HOT and COLD. The color of choice for porcelain fixtures is white. ““We decided eight years ago that we wouldn’t sell other colors,’’ says Barbara Sallick, a founder of Waterworks, a chain of luxury bath stores in the Northeast. ““When we look at all the pink and green and black bathrooms we’re replacing now, we feel vindicated. No one has ever come back and said, “I can’t stand my white bathroom’.’’ The most common finish for metal fittings is polished nickel, which is a little like chrome but gleams with a much warmer and more inviting cast, as the discerning consumer about to plunk down $1,500 for a faucet can easily see.

Of course, you can still always get gold.

PHOTOS (COLOR): The throne room: From her bathroom, Paul can gaze outdoors (above) or warm herself by the fireplace (left), next to the entrance to the master bedroom

NO, INSTALLATION IS NOT INCLUDED When you want to make a big splash, there’s no limit on price. Some examples:

Fancy Sink: Marble counter and nickel washstand. Price: $3,538.

Waterfall Spa: Your own private Niagara, without tourists. Price: $6,418.

Shower Fixture: Retro fittings in polished chrome. Price: $2,258.

Mosaic Tile Floor: The Pompeii look. Price: Up to $200 per square foot.