Katleen Van Roost and her children

Like no other phrase, the Hamptons summons up a vibrant host of summery associations. Glorious, powdery sand beaches to soothe and massage bare feet. Deep, white-slipcovered sofas you want to sink into and never leave. The perfect balance of sun and breeze to warm, then cool your face. And enough overheated traffic to make a person curse it all.

For better or worse, all of the above holds true for the East End of New York's Long Island, where the coast is heaven and the roads are, well, the other one. Relax? Most people here aren't looking to, preferring the lively social scene that percolates away at tennis courts, restaurants, cocktail parties, and benefits. One would assume that's why Katleen (here with her children, Ileana, 2, and Sebastian, 4, at their home's front entrance), bought and renovated her house in the Hamptons community of Wainscott—and why she flies her family across the Atlantic Ocean to spend every July and August here. Surely, she must adore the go-go social scene.
A living room still life

But Katleen's motivation is just the opposite. To hear her tell it, she, her husband, and their two children may be the only people who come to the Hamptons for the same pleasures that first drew beachgoers over a century ago. The fresh air and sunshine. The open, farmed fields. The lusciously wide sandy shore. And the splendid isolation. The social scene, to her, is completely foreign and virtually invisible.

A single leafy branch and a lamp made of driftwood sit on an antique oak refectory table in the living room.  
Katleen Van Roost's peaceful patio

On Katleen's peaceful patio, teak patio furniture by Dutch designer Piet Boon is covered in water-resistant fabric. The handmade clay planters are from the Belgian company Atelier Vierkant.

"For New Yorkers, I know—it's Manhattan on the beach," Katleen says. "We know lots of people who go to Sardinia or places like that—and it's hard to say no. Here, we're not forced to be part of the scene, which really gives us the ability to unplug."  
Katleen Van Roost's Hamptons living room

According to Katleen, Hamptonites—whose favorite topic is grousing about how congested the area has become—might want to consider just how good they've got it.

"It's relatively uncrowded," Katleen says, with the cool certitude of a woman who deals in numbers. "Even in August, it's nothing compared to the Italian coast. The Mediterranean is really crowded, and the whole European coast is built up from one end to the other with apartment buildings. The fact that there are houses here, no flats at all, is so different and refreshing."

In her living room, a light fixture from Fontana Arte hangs above linen sofas by Christian Liaigre. All it takes is one unexpected moment—like this oversize pendant lamp—to infuse a neutral scheme with drama.  
Kids work at a chalkboard table

Katleen first traveled to the Hamptons nearly a decade ago while working and living in New York City, and she was immediately entranced. "It was the topology of the place," she says. "You have countryside next to the beach. You can bike-ride to the ocean. Nothing like it exists in Europe."

A few years later, she and her husband fell in love with a home they were renting for the summer. "It had a saltbox feel," she says, comparing it to the first colonial-era houses built in the area hundreds of years ago. To her eye, the nonlinear rambling flow of the architecture—comprised of small structures linked with sunlit passages—made the result resemble a group of farm buildings. Without the hay. Or the smell. "But at the same time, it was very modern," Katleen adds, like some geometric abstraction of an all-American country house. By the end of that season, she and her husband had purchased the place from the architect who had just built it for himself.

Sebastian and his cousin, Maxime, 11, play at a chalkboard-topped table from Offi.
Katleen Van Roost's Hamptons kitchen

Though the house had been the ideal rental, it was not yet the ideal home. "I'm a purist and a perfectionist," explains Katleen, who embarked on a remodel from Europe, where she was also decorating her family's London home (while holding down a job and raising a young child, with another one on the way). Being far more exacting than most amateurs (much less amateurs working from thousands of miles away), she enlisted New York designer Felicitas Oefelein to assist her with the details that could only be handled on-site.

The Van Roost's kitchen is equipped with a Viking stove, a Sub-Zero fridge, and Artemide light fixtures. An island loaded with drawers eliminates the need for overhead cabinets, making minimalism possible in the kitchen.
The master bedroom

Together, Katleen and her designer, created an entirely new entry, replacing the existing front door with a far more dramatic one that pivots instead of swinging. The original, standard-issue kitchen and bathrooms became remarkable testaments to luxurious minimalism. Now, stainless-steel appliances reflect a sizable Corian island that camouflages the majority of the kitchen's storage. The master bathroom contains not one, but two showerheads, both set behind a glass wall that defines, yet doesn't divide, the space. Steps away, the bathtub is a simple white box, albeit a box that's 6 1/4-feet long (almost 20 percent longer than traditional tubs). And while the palette consists of whites and grays, the materials—marble and limestone—are rich and textured.

The master bathroom has everything—and then some. But thanks to the floating sink console, simple boxy tub, and transparent glass shower wall, the room still feels serene. And why stop at his-and-her sinks? Katleen installed two stainless-steel showerheads in this airy, open-sided stall.
The master bedroom

A custom oak screen doubles as a headboard and adds intimacy to the master bedroom, where Katleen accessorizes with Matteo white linens and oak chairs from Birdman Furniture.

"I wanted to work with the elements as opposed to prints or colors," Katleen says of the home's spare aesthetic. "In London, we have a proper flat. We have a contemporary art collection there—but we didn't want that here. I wanted the walls to be bare, to strip it down to the bare essentials, so I could just play with tonality and texture. So everything's neutral, beiges and grays and whites, and old-wood pieces that feel used and loved."  
The outdoor shower

One man who deserves some of the credit for the house's stark and serene appearance—Parisian furniture designer Christian Liaigre—has never set foot in the place. Much of the furniture came from Christian, including the living room's linen sofas and divan, a pair of dining room tables, and some of the bedside tables. Katleen bought a great deal of his furniture for their London house at the same time. "We're good customers," she says with her characteristic dry restraint. "He's my favorite designer by far."

A stainless-steel outdoor shower—installed along the path to the front door—keeps the kids cool.  
Swinging in the backyard

With Christian's—and Felicitas's help—Katleen has created a symphony of texture, finish, tone, a getaway for her family in the otherwise hectic Hamptons. Here, having fun doesn't mean attending an evening fund-raiser, but watching the kids gallop across the yard on a horse-shaped tire swing or cooling off beneath the outdoor shower. "I'm a very calm person, and this place just oozes calmness," Katleen says. "That's a real reflection of who I am—we really feel at home here."

Katleen's nieces (from left) Maxime and Elise play on the horse-shaped tire swing that hangs in the backyard.  
Window seat in the guest bedroom

That's the benefit of getting everything done right. Once you're done, there's nothing left to do but relax.

Cushions and a little carpentry made a window seat out of this once-unused space in the guest bedroom.