If personality transforms a house into a home, then the recently constructed beachside residence of interior-design maven and ceramics luminary Jonathan Adler and his husband, window-dressing legend, creative ambassador-at-large of Barneys New York, and all-around bon vivant Simon Doonan, is one of the greatest residences on New York’s Shelter Island. After spending years in a 1970s A-frame in the area, the creative couple decided to build their first-ever ground-up project. “We wanted to crank it up a notch,” says Adler. They knocked down a small cottage on 1.25 acres of beachside land and started anew with the help of Connecticut-based firm Gray Organschi Architecture. “We wanted warm, rustic modernism,” Adler continues. “It’s a little California, a little bit Japanese, and a little bit Swedish.”

The result is a one-story, 2,800-square-foot structure, with four modestly sized bedrooms, a pool, and a variety of private indoor-outdoor spaces, whose exuberance is only surpassed by Adler and Doonan’s own outsize charisma. “It’s located on Gardiners Bay,” says Adler, “facing due east, so the sun rises right outside of our house. It blasts us awake every morning.” It’s all perfectly suited to Adler and Doonan’s lifestyle. “Every day is like a tampon commercial,” says Adler, “whether it’s running on the beach, going for a bike ride, or paddleboarding.”

In the home’s interiors, Adler’s design aesthetic took flight—with a variety of theatrical touches from Doonan. Nearly all the pieces are Adler’s, and the house is a testing ground for objects that might make their way into one of his 26 stores, like the Ravello cocktail table, in the living room, with a turquoise-blue glaze that emulates the ocean. Adler started experimenting with the table’s prototype at the same time that house planning began. “I think that everything I do informs everything else I do,” Adler says. “It all goes into production.” Shots of color from the ’60s and ’70s are everywhere, and certain custom tactile elements add depth and warmth. For example, a seating area in the living room is adjacent to a custom tile wall of Adler’s own design. Exercises in scale—another Adler trait—are evident in an oversize macramé creation by artist and set designer Andy Harman. “I wanted to bring a sense of California craft in but tweak it a little bit,” says Adler. “It’s a super macramé house but done through a trippy contemporary lens.”

Upholstering the walls in neutral grass cloths made the house’s four small bedrooms—one of which is used as a gym—extra cozy. Objects and furniture constantly rotate through: “My poor, long-suffering husband never knows what he’s going to come home to,” says Adler. “Even if it works, I always think there’s a better way.” Not to be outdone, Doonan contributed with elements such as a shelving unit for books and ceramics, made from humble recycled-wood planks, and, in the master bedroom, a fiendishly defaced portrait of George Washington, featuring an eye-patched first president. “We didn’t want it to feel modernist-precious,” he says. “It had to feel modernist-boho-chic, like Big Sur.”

The relatively small size of the house and the black-painted exterior are two key facets of the project that make it stand out amongst its neighbors. And why the ominous color? “Painting things black is not an insane, punk rock gesture. It’s actually a very landscape-friendly thing to do. It’s the white houses that are quite jarring on the landscape,” Doonan says.

In keeping with Adler’s kitsch-heavy and ultra-friendly aesthetic, the couple felt it was important for the house’s materials to balance out the austere-looking structure. “People build beautiful, modern houses today, but sometimes they look too precious,” says Doonan. “I like surfaces that use recognizable materials, like Masonite, and mixing them in with Jonathan’s custom tile works and stuff like that. That’s what makes it feel like a beach house and not a bank floating in the middle of a lawn.” Warm but readily available—and therefore economical—red cedar wood is used for the ceiling throughout the house, extending to the cantilevered awnings around the main building and the side of the pool pavilion outdoor seating area. The interior walls are painted, rough-cut pine. “It feels like Fire Island in that sense and cranks up the rustic feel of the house,” Adler says.

The site’s drastic grade change—almost a full story from the front to the back—challenged architect Lisa Gray, but she used this potentially negative trait to her advantage in choreographing the flow through the interior. “They wanted a really big, open space for the living room, but they liked the idea of keeping the level changes, when possible, inside the house,” she says. When visitors arrive, they step down into a courtyard, and when they enter the house, they step down further into the living room. “These gentle level changes make these sequences of indoor and outdoor space feel really, really private,” Gray says.

The rejection of a beachside-cottage look helps the couple feel at home all year long, even in winter, when tampon-commercial activities are difficult. “The sensory deprivation is great,” says Doonan. “It is a bit like The Shining but only in a good way. Hopefully, we won’t turn into Shelley Duvall and Jack Nicholson."