Once a mere outhouse, the bathroom has become one of the most important rooms in the home — for reasons you normally wouldn’t expect.

“It’s like people want to live in the bathroom,” a senior vice president for Halstead Property, Brian Lewis, said. He is also the host of two HGTV shows, “My Home is Worth What?” and “National Open House.”

The fascination may be more of a financial than a personal one. “If you have a really ugly bathroom, it can take down the value of your property,” interior designer Robin Wilson said. “Bathrooms and kitchens will sell a home,” Mr. Lewis said.

Before whipping out the blueprints for a brand new loo, “first you have the check the wallet, because it ain’t cheap,” he said.

But once the finances are squared away, would-be home decorators may find themselves facing an even greater challenge: the building board.

“If you’re trying to approach a board who you think is rigid, the best thing to do is approach with a detailed analysis,” Mr. Lewis said. “Boards like information. Theories and ideas scare them.”

“One of the things we do is speak to the building supervisor,” says the principal of design firm Ageloff & Associates, Scott Ageloff. He is also the dean and vice president of academic affairs at the New York School of Interior Design.

Another thing he recommends is obtaining a copy of the building’s Alteration Agreement, which provides general guidelines for the types of renovations that can or cannot be made.

“It requires homework,” he says, but it is well worth it. “There’s no sense in spending the time and money in designing something that won’t be well-received by the building.”

Those who traverse all of the obstacles have some of the following trends in décor, design, and architecture to look forward to:

Bigger is better.

“People are growing their bathrooms,” a senior vice president for Halstead Property, Brian Lewis, said. And as square footage increases, so do the fixtures within. Medicine cabinets have become so large that “you could fit a whole Duane Reade in there,” he said.

“I like showers that don’t need shower doors because they’re so large,” renowned interior designer Vicente Wolf said. He dislikes sitting in a tub, but once had a client who requested a bathtub with a bench that could accommodate two. But none were quite as large as one he recently installed: at 35-by-40 feet, the bathtub is more spacious than some Manhattan bedrooms.

It takes more than one to screw in a light bulb.

“Bright lighting, like fluorescent lighting, is out,” interior designer Robin Wilson says. For a soft glow with a cool burn, she recommends the use of Xenon bulbs, which are more energy-efficient than halogen.

Some property developers and architects are taking it several steps further, using multiple light sources in a single room.At the Element, a luxury condominium near Columbus Circle, the type of lighting can vary from one square foot to the next. Cove lighting, which involves the installation of bulbs within a recess in the ceiling, lines the bathtub. Ambient glows and indirect lighting hit other areas in the room. “The lighting is very evenly distributed,” the managing partner of development firm COALCO, Edward Baquero, said. “There’s not a lot of spotting.”

Telephoning from the bathroom is not rude.

With technology encroaching upon nearly every aspect of everyday life, it was only a matter of time before it reached the bathroom. Those with multiple showerheads can control which head (or heads) water emanates from with a diverter, while a thermostatic device allows one to pre-set the temperature of the water.

Aside from the bevy of waterproof phones and remote controls on the market, it is possible to install flat panel televisions within a medicine cabinet mirror. The television attaches to the mirror with a magnet, according to the executive vice president of real estate marketing firm Marketing Directors, Monica Klingenberg. When the television is on, the image is visible through the looking glass. When it’s off, the only thing that can be seen is a reflection. The caveat: “You have to be organized,” because the device needs to be plugged into an outlet within the cabinet.

Tomount a television onto other surfaces, there’s also the option of surrounding a television set with aquarium glass, says interior designer Robin Wilson.

For the visually apathetic, there’s the option of installing a sound system within the bathroom. “All of the speakers we make are waterresistant,” the president of Niles Audio Corporation, Frank Sterns said. They can also be implanted within a wall so that they can be heard and not seen.

At times, the sound systems can also be a matter of practicality. “It’s a sound-masking system,” the principal of interior architecture and design firm Ageloff and Associates, Scott Ageloff, said. “It’s another way of providing privacy.”

Movie stars aren’t the only ones with powder rooms.

Also known as a down bathroom or guest bathroom, powder rooms have become increasingly important for the host. “It’s an opportunity to do something over the top in a space that you don’t use very often,” Mr. Ageloff said. For a client who collected Indian artifacts, he recently designed a powder room that featured stenciled depictions of Indian life.

According to Mr. Baquero, this new American trend has long been popular in Europe and Latin America, where second bathrooms are fairly commonplace.

Bathtubs are as varied as the people who use them.

Once limited to being constructed from white porcelain, bathtubs are now made with everything under the sun. “Materials used today are much broader than they used to be,” says Ms. Wilson.The usual suspects — porcelain, corian, marble — are still around, but they’re now being joined by copper, nickel and sometimes resin. One of Mr. Ageloff’s clients had a tub hand-made in concrete.

Mr. Wolf, on the hand, has seen Infiniti tubs rise in popularity. Designed to trick the eye, they provide the illusion of never-ending water. And for those who generally have difficulty making up their mind, Mr. Wolf has a solution: “Now there are tubs that can change color.”

Singing in the shower rivals singing in the rain.

If the types of bathtubs seem to have multiplied, then showerheads are looking to give them some competition. No longer can the shower only be on or off; it’s possible to bathe in rain, steam, or a full body-spray.With a head that is mounted into the ceiling, the stream of water is often gentler as well, simulating a soft downpour rather than a raging thunderstorm. “Although the rain shower can be quite delightful, it doesn’t always get the job done,” says Mr. Ageloff, who recommends supplementing the shower with an additional water source.

Ladies who want to avoid washing their hair might want to try a body shower, in which multiple sprays aim southward of the neck. Residents of the Oculus Condo complex can program their showerheads to dispense any combination of steam and water, according to the site’s developer and the president of Alchemy Properties, Kenneth Horn.

Cold floors are almost as bad as cold water.

Though the newest projects in Manhattan are as unique as the people who populate this city, one thing that developers can agree upon is radiant heating in floors. At both the Onyx Chelsea and the Oculus Condominium, the technology is incorporated into every master bathroom.

“The best way to look it is that it’s a heating pad”beneath the floor, said Mr. Horn.

“It’s an amenity that buyers are very receptive to,” said the CEO of CORE Group Marketing, Shaun Osher, who oversees marketing for the Onyx Chelsea. A thermostat sets the temperature of the floor, but once the temperature of the entire room reaches that on the thermostat, the entire system shuts off. “It would never be uncomfortably warm,” he said.

Though still somewhat uncommon, this innovation is hardly new. “The Romans were doing that — they had floors that were heated with flames from below,” said Mr. Wolf. Then and now, “It speaks of your wealth.”

But within this luxury, there is also a touch of pragmatism: “Because heat rises, it makes sense to heat the floor,” Ms. Klingenberg said.

Texture is not only for fabric.

“Some of the tiles are becoming very sophisticated,” the owner of the interior design firm Period, Rick Livingston, said. He cites cross-hatched tiles as one common example, but glass and patterned tiles also fall into the same category.

Unusual textures can sometimes crop up in the most unusual of places. For one project, Mr. Wolf covered cabinet doors in sharkskin. Washington D.C.-based Sogol Decors has adorned bathrooms with leather furnishings.

Not even walls have to be smooth. In her work, Ms. Wilson sometimes uses paint that provides a suede finish. “When you first walk into the room, your gut says ‘Oh my God! They have suede on the wall!'” A sand finish also exists, but no matter which type of textured paint is preferred, she cautions, an expert should be the one to apply it.

For nature calls, the bathroom is the place to be.

Synthetic materials need not apply: natural elements are on the rise. Wood, glass, lava stone, and even gems have all found their ways onto countertops, vanities, and other furnishings.

In some instances, improvements have been made on Mother Earth. According to a sales associate at the DJK Residential brokerage firm, Kathryn Higgins certain glass tiles are now slip-proof. “They’re very high-end looking, but you’re not going to break your neck on them.”

At other times, it’s convenient to take advantage of what nature has to offer. Since granite is nonporous, it does not absorb stains, making it a prime choice for counter tops. “All you have to take is one damp cloth, and it’s restored,” says Ms. Higgins.

“We’ve done a few bathrooms with onyx,” Mr. Ageloff said.”If it’s cut thinly enough, light can pass through it.” With lighting installed beneath an onyx countertop, the piece can glow.

Yet natural does not always mean simple. On one recent excursion, Sogol Afsharvajan of Sogol Decors came across several semi-precious stone tubs. “The entire bathtub was amethyst and it had a matching sink.” According to Ms. Afsharvajan, the set can be acquired at the cost $120,000. “The sky is the limit,” she says. We make dreams come true- that is our forte.”