Decorator Jennifer Post Dreams Up a High-in-the-Sky Pied-à-Terre in the Middle of Manhattan

White leather Quadra sofa by Poltrona Frau

Thirty-three floors above Third Avenue on the Upper East Side, a door opens into an extraordinary space, a dramatic synthesis of light and air, low white furnishings, and carefully curated colorful accents. If not for the wraparound views that anchor the 1,400-square-foot two-bedroom to Manhattan, with the East Side and Central Park spread out like a Lego kingdom below, a first-time visitor might almost feel as if he were in a spaceship, or on a cloud.

Interior designer Jennifer Post, whose clients have included Simon Cowell and Jennifer Lopez, has built a jewel box in the sky for a couple from Mexico who make monthly pilgrimages to the Big Apple. “The objective was to open up everything that faces the park—I wanted to make it very pure, with bursts of color,” says Post, who upon seeing the original 1980s construction, with its dark parquet floors and a foyer that blocked the views, stripped the space down to its bare bones. She removed light-obscuring walls, including that of a guest bedroom adjacent to the living room, replacing it with sliding glass doors and a curtain that can be closed for privacy. Sleek Italian furnishings, such as beds by Cappellini and a glass-topped dining table by Zanotta (its base resembles a sculptural sawhorse), are high-end, but not at all serious.

Guest bedroom with Serena and Lily Pickstick matelasse bedspread

“All the colors are very positive, the white is bright and fresh, and nothing is harsh,” says the Manhattan-based Post. “My clients gave me a lot of creative freedom. They basically said, ‘We want white, we want happiness, we want to have one big open space along with a big master suite.’”

Though the apartment does indeed appear spare on first glance, there is plenty going on amid all the open air. Subtle gray-stained maple floors smartly balance the preponderance of white, and hallway closets by Poliform have the texture of waves or windswept dunes. In the guest bathroom, ribbed ceramic floor tiles by Gypsum provide added dimension. Doors, drawers, and cabinets close with satisfying, luxurious clicks. Silk carpets, custom made in Nepal, squish dreamily underfoot.

There is a harmony-inducing, unified effect among the pieces from room to room, with furnishings—like the apartment itself—that appear to float, such as a chartreuse lacquer Antonio Lupi buffet in the dining area and a pair of Poltrona Frau sofas, anchored by a vibrant green banana silk carpet from Doris Leslie Blau. Edited down to these essential luxuries, the apartment has everything—except clutter. “The homeowners are extremely tidy and meticulous, and I am too,” says Post. “It’s low maintenance and has a great Zen quality overall.”

Even by Post’s standards, though, the apartment is far from the most minimal of her projects. “This pied-à-terre is more like a chic spa!” she enthuses. “It’s completely decked out for iPads and iPhones, and the kitchen is roomy and made for cooking—the wife is a professional chef, so it was extremely important.” Post outfitted the 200-square-foot kitchen with a Gaggenau stove and mini Miele dishwasher. “The couple have a lot of friends in New York and love to entertain,” the designer adds. “They cook Mexican food, have drinks on the balcony, and then go out to the theater or to the movies. It’s important for me to pare spaces down to the bare essence—to just what a client needs. They might be minimal, but because of that, they’re beautiful.”

A version of this article appeared in the May/June 2014 issue of New York Cottages & Gardens with the headline: Post Modern.