Until getting married and having a child, veteran fashion editor Dani Stahl had subscribed to the Carrie Bradshaw school of decorating: shoes filled her kitchen cabinets and necklaces adorned her walls. When she and her financier husband David Kirsch purchased a weekend home outside the city four years ago, “I was basically like, ‘What’s a chair?’” she quips. At the time, the couple didn’t have the budget for an interior designer, but Stahl tapped her longtime friend Chiara de Rege, the decorator behind the Carolina Herrera and The Wing flagships, for a few pointers. “She bestowed on me different websites and names, so by the time we got to buying an apartment I had the basic stuff down,” says Stahl.

Dani Stahl, seated in a TMBO lounge chair covered in a Zak + Fox stripe , in the living room of her Upper East Side apartment.

A native Manhattanite, she knew she wanted to return to the Upper East Side neighborhood she grew up in when she and her husband started looking. Both sets of grandparents lived uptown and Stahl’s alma mater, where the couple plan to send their five-year-old daughter, Sunny, is also nearby. “It’s home,” she says. Beyond geography, there was just one caveat—albeit an unusual one: Stahl harbors an intense elevator phobia. Her husband had visions of an aerie, but “I can’t sign up to walk a million flights for the rest of my life. So we had agreed that the third floor would be our floor. Once you limit your search based on that,” she continues, “there’s only going to be so many that come up.” When they happened upon a listing in a 1960s white brick building along the stretch of Fifth Avenue known as Museum Mile, she wasn’t sure. She had had notions of a classic pre-war six. But Kirsch was sold: the treetop views onto Central Park, the ample space for family living. The apartment would need a gut, but he saw the potential. In hindsight, Stahl admits, “sometimes with me the best things are the ones I’m not obsessed with at first. It quickly grew on me.”

She didn’t need to think twice about who their decorator would be: “Chiara was my first call.” To handle the renovation, De Rege suggested New York–based architect James Sanders, whose colorful resume includes designing actor Molly Ringwald’s apartment, penning the acclaimed early 2000s book Celluloid Skyline: New York and the Movies , and co-authoring a documentary on the city that received an Emmy Award. The apartment was in its original condition, which is to say, “the 1961 architectural plan, built around the standards and expectations of the long-vanished Mad Men era,” says Sanders, citing a dreary galley kitchen, small bathrooms, and cramped corridors leading to the bedrooms in the rear. He knocked down walls and reconfigured spaces, creating a gracious kitchen that opens onto the living area with a family breakfast nook in between. “The flow is phenomenal,” says Stahl. “All I want to do is entertain.”

In the sun-filled living room, a custom Maison C chaise upholstered in a LuRu Home floral and a Zak+Fox velvet sits in front of a Suite NY pouf . Just beyond, a window seat offers treetop views onto Central Park.

De Rege talked the couple out of trying to imitate old New York moldings, instead channeling the postmodern era of the apartment. She notes, “Rather than the Mad Men –style of design which is so often found in those buildings, we leaned in the direction of Italian post-war.” The designer grew up summering with family in Italy, so it’s a genre she knows well. In the living area, she designed a floral chaise based on the Piero Portaluppi curved sectional in the drawing room at Villa Necchi. (It will be part of a new furniture collection for Maison C, the wallpaper and fabric company she cofounded with Costanza Theodoli-Braschi.) A chandelier in that same room, meanwhile, took cues from one Stahl saw and fell in love with in Margherita Missoni ’s house in Varese. De Rege worked with the same artisan in Murano who had done the lighting for the Carolina Herrera store to create the cascading glass shards.

A breakfast nook banquette is covered in Pierre Frey fabric with a custom table by Chiara de Rege and Giardino Botanico manfredi stools .

“Dani really wanted the unexpected,” she notes. “She loves color and she wasn’t afraid of pattern. She has such a well-trained eye from the fashion world that her palette is very sophisticated.” When De Rege presented her with fabric options, for example, “she would always select the Pierre Frey or Decors Barbares. I said to her, ‘You always choose the Celines, never the Zaras.’” Needless to say, De Rege was happy to oblige. The breakfast banquette is dressed in a bold, graphic Le Manach with scalloped edging that winks back at Portaluppi. Knowing that it would be a family-centric space, De Rege rounded it out with flower-shaped brass and velvet stools tucked around a table on yellow-dipped metal legs to make it “playful and fun.” Hidden drawers underneath artfully conceal Sunny’s craft projects.

The open kitchen features a checkerboard marble floor from Exquisite Surfaces with a Nemo Tiles backsplash. Calypso Antigua suspension lamps float above the kitchen island with leather stools by Michele Varian .

The open layout made the kitchen design a particular focus. De Rege played off of Sanders’s wood-wrapped cabinetry with Imperial Danby stone topping the steel-framed island (“it’s warmer than Carrara,” she notes), a backsplash of luminescent midnight blue tiles, and a checkered marble floor that’s “an ode to the more traditional pre-war apartments Dani grew up in. So many apartments open up the kitchen to have a loft-like feel, but then basically dump a suburban kitchen in,” De Rege says. “I really wanted a differentiation in the floors.”

Art was another focal point. After De Rege introduced her client to Field Kallop, a fellow native New Yorker who had attended the same primary school as Stahl, the homeowners commissioned two psychedelic works from the artist to surmount the dining table. “They are out of this world,” says Stahl. “I like using the word kaleidoscopic over and over.” Adding to the trippy vibe, Stahl placed them opposite a cube mirror by Bower Studios. “I sort of look at rooms like outfits,” she says. “I don’t know all the fabric houses or where to get everything, but visually I know how to put things together.”

Maison C wallpaper livens up the powder room. The Drummonds pedestal sink and faucet are surmounted by a Menu Design Shop mirror .

A sisal grasscloth by Twenty2 wraps the walls in the entryway, where a Samuel & Sons trim frames the doors. Kevin Mackintosh photograph of an ostrich from Clic Gallery.

Her personality pervades throughout. In the corridor leading to the bedrooms, the closet doors that run down the length are framed in red grosgrain trim that, De Rege says, "is so Dani. Rather than just entering something with white painted walls, there’s a little pop.” Maison C wallpapers set the scene in the jewel box powder room, the den, which is a cocoon of pattern on pattern, and Sunny’s bedroom. “The thing I love about her room is that it’s not babyish,” says Stahl, who suggested a sophisticated red color palette that her daughter could grow with. A tent of a John Rosselli fabric hosts all manner of imaginative play. “It’s the hot place to be. Dani is always sending photos of Sunny having play dates in there,” says De Rege, whose own daughter, Phoenix, is a recurring guest. After one recent tête-à-tête, “Phoenix came to my office and told my team that she wanted Sunny’s bedroom but in a pink colorway,” her mother adds with a laugh.

A Pierre Frey wall covering wraps the walls of the primary bedroom. The roman shade is of a Decors Barbares fabric and the bedspread is Olatz.

The primary bedroom is the one place in the apartment where the designer and client took a more restrained approach. De Rege recalls with amusement that Stahl’s mother was particularly opinionated with respect to the couple’s lair. “Joan was adamant that the room should be an oasis. She said that they need to walk into something calm and hotel suite–like. Ultimately, I agreed, and we kind of designed to her mom’s directions.” A serene Pierre Frey silk wraps the walls, reflecting the room’s natural light and beautiful park vistas.

Stahl’s Chanel bags and statement shoes have also found a happy home via a well-appointed walk-in closet—although old habits die hard. Careful observers will notice one or two dressing up a library shelf here and there. “I didn’t get all new accessories with Chiara,” Stahl says with a wink. “I sort of came accessorized.”