She climbed her way back to the top of the pop charts, but nothing's more satisfying to Mariah Carey than coming home to her penthouse pad in Manhattan.

It would be difficult to describe the past year as anything short of a triumph for Mariah Carey. Her album The Emancipation of Mimi was the best-selling CD of 2005, won her three Grammys (she now has five), and helped the 37-year-old singer tie Elvis for the second most number-one singles (17) of all time. But Carey also staged a miraculous comeback on the domestic front: overhauling her 12,000-square-foot Manhattan triplex after a water tower burst, soaking much of her elaborately hand-painted, antiques-laden, chandelier-strung abode.

"Everything was perfect and then - whammo! Talk about a leak!" says Carey's interior designer, the renowned N.Y.C. decorator Mario Buatta. "All the furniture had to be taken out and put into storage, every wall had to be repainted, the baseboards had to be ripped out - the place had to be completely redone. It was a nightmare."

A garden-variety superstar might have lost her cool, but Carey, who rented a house in Bel-Air while the damage was being repaired, didn't get all worked up over the matter. After a few difficult years she's in a good place - literally and figuratively - and on this balmy March evening she's utterly relaxed in her newly dressed-up digs, despite being more than an hour late for a flight to L.A. The plane isn't going anywhere without her, though: It belongs to movie mogul Jeffrey Katzenberg, who sent it to fly her to his Oscar party, at which she has agreed to perform. "Remember, Mariah, it's not your plane," her personal assistant anxiously reminds her. "Oh, right," Carey replies nonchalantly. "I forgot."

Downtime is so precious to Carey that it's easy for her to overlook such relative trifles. But as far as her over-the-top image is concerned, she is always ready to have a good laugh at her own expense. "The greatest thing about this apartment is that it's the first place I've owned by myself, so it's all me," she says. "If someone else ever bought it, she'd have to be a total diva!" Plush sofas, taffeta curtains and hallways dripping with glittering sconces make the triplex "art deco-y and Old Hollywoodish, the kind of place I dreamed about having when I was little." After her parents divorced, when she was 3, Carey and her siblings grew up living with their mother in 13 successive houses on Long Island, which left her feeling "like a rug was literally being pulled out from under me. I remember saying to myself, 'I want to have a good life and feel secure,' I had to have faith. That's how I got over every obstacle along the way - by visualizing and believing in something better."

During the early years of her career, Carey married music-industry titan Tommy Mottola and had a taste of the world she once could only imagine, living on a majestic 50-acre estate outside N.Y.C. (the couple later divorced). "Unfortunately this was a time when all I was allowed to do was sit there and pick out sconces," she says. "I can still spend hours talking about door handles." A remnant from that era, which sparked her passion for interior design, now anchors her informal family room: an ornate, hand-carved cherry mantelpiece featuring flowers, hearts and her trademark emblem, a butterfly. "This piece took two and a half years to finish," Carey says. "It's a little garish, but I love it because of what the butterfly represents: freedom."

Both extravagant and comfortable, Carey's apartment reflects her hard-won maturity and independence in almost every corner. Hallmarks include glazed peach walls (they required eight coats of paint), a marble steam room with a waterbed (the humidity is good for her voice), and a brand-new Marrakech-inspired solarium that looks like something out of Arabian Nights. "After my roof garden is finished and I put a hot tub out there, I'm going to call this room Chez Mimi," she says, referring to her nickname. "I won't go to smoky clubs anymore. I'll party with my posse here, and we'll watch the sun rise."

Surprisingly, her biggest indulgence looks anything but: a chipped white baby grand piano, which set her back $662,500 at a Christie's auction of Marilyn Monroe memorabilia. "I could have gotten the 'Happy Birthday, Mr. President' dress or whatever," Carey says, "but that would have represented Marilyn Monroe's stardom, whereas the piano belonged to her mother and was a piece of her childhood." The singer identifies strongly with the often misunderstood icon and has even accessorized one of her bathrooms with photographs of the star and other mementos. "She had such a childlike quality," adds Carey, who tends to embrace her own youthful impulses more often than not. Her fans love to send her stuffed animals, butterfly figurines and Hello Kitty keepsakes; she has created a sort of shrine to the latter in another small bathroom. "Lindsay Lohan, Sean Lennon and I had a jam session in there the other night. They were obsessed with my Hello Kitty bathroom."

If the apartment has a pulsing heart, though, it is most certainly the family room. When Carey's father died of cancer in 2002, he left behind dozens of family photos that she had framed and hung from pink ribbons on the walls. Other inherited pieces include a flag from his stint in the army, cards that she had given him as a young girl, and her grandmother's pink hand mirror, which has a yellow butterfly painted on it. "My father was going to give the mirror to me as a birthday gift, but then he passed away," Carey recalls. "He had saved all kinds of things for me, and I never knew it. I never knew he cared about me like that. This is the stuff that really matters."