The quiet, laid-back atmosphere of Shelter Island, nestled between the North and South Forks of Long Island, has long made it a special place for John and Christine Gachot. “I basically grew up here,” said Mr. Gachot, 55. “My family came every summer.”

When he married Ms. Gachot, 56, she became part of the tradition. And even after the couple founded their busy Manhattan design firm Gachot, which is skilled at creating casually cool interiors layered in warm lighting, soft colors and vintage furniture, they continued to return. In between designing the Shinola Hotel in Detroit, New York bars such as Jac’s on Bond and Pebble Bar, and homes for clients including Marc Jacobs, Shelter Island remained the place they escaped to with their two sons to relax, recharge and let their imaginations wander.

In 2017, they bought a house they had admired for years, which came with a 19th century carriage shed. The shed reminded the Gachots of an outbuilding Mr. Gachot’s father, the sculptor Richard Gachot, who died in 2018, had used as his studio: a former ice house behind his home in Old Westbury, N.Y.

“He had two club chairs in there and a little bottle of whiskey in the safe, and that’s where we would have all our important father-son meetings,” Mr. Gachot said.

Inspired to create something similar, he and Ms. Gachot transformed their carriage shed into an art studio that doubles as a recreation room, with a Pac-Man arcade game, pool table and vintage slot machine.

“Whenever I’m out here, I’m painting and drawing every morning,” Mr. Gachot said. “Then at night, the kids take it over.”

The couple highlighted a few of the objects that help make it a special space.

Easy Upgrade

Mason jars, about $1 each at Ace Hardware

The Gachots love upscale furniture and accessories, but they also appreciate well-designed utilitarian goods. For storing his paintbrushes, markers and pencils by the fistful, Mr. Gachot has found there are few better containers than old-fashioned Mason jars. “They’re just at the hardware store, and you can go buy them by cases of a dozen,” he said.

“We actually use them for everything,” Ms. Gachot added. “If we’re hosting a party, we’ll go get a case and put candles in them. I use them for cut flowers all the time. You can put them out as water glasses. Sometimes, we get really big ones and mix batch cocktails in them.”

In almost every situation, the jars look good while eliminating concerns about more precious glassware getting broken. For Mr. Gachot, there’s another reason to use them: “My dad used them in his artwork.”

Splurge

Vintage Fritz Hansen lounge chairs, $25,000 for the pair at Morentz

“I’m a big Danish furniture fan,” Mr. Gachot said, and one of the pieces he had long admired was a sheepskin-covered lounge chair made by the Danish manufacturer Fritz Hansen in the 1940s.

“We always wanted a pair of them, but I could not get John to splurge,” Ms. Gachot said, because the price tags always ran into five digits. Mr. Gachot finally decided to treat himself, however, when the couple spotted these vintage chairs at Morentz, a design gallery in the Netherlands, in 2023.

“I think of them a little like artwork,” Mr. Gachot said. “But it’s not just hanging on your wall. You live with them and sit in them. It’s really life-enhancing.”

“A really solid, good chair is an investment piece, and it’s something you’ll have forever,” Ms. Gachot said. “Your sofa or your dining table might not fit in your next home, but your chairs will. They can travel with you for a long time.”

One of a Kind

Tin flowers by Richard Gachot

When Mr. Gachot’s father died, he left behind a studio full of his creations. Many of those pieces are now proudly displayed in the Shelter Island shed. “It rekindles all those memories of sitting in the ice house and having conversations with my dad,” Mr. Gachot said.

Built with found objects, some of the pieces reflect pure creative experimentation, such as a kinetic sculpture featuring a hunter aiming a rifle at ducks, which is driven by a hand-drill gear and wind-driven propeller. Other pieces carry personal stories, including these tin flowers, which the artist made for family.

There is even a dog made from Café Bustelo coffee tins. “His dad made me that little Bustelo dog,” Ms. Gachot said, when he learned that she had always wanted a puppy.

Beyond the memories, the pieces also provide inspiration. The Café Bustelo dog, for instance, has given Mr. Gachot an idea for a future project, Ms. Gachot said: “John’s going to make a Peroni version of it.”