NANTUCKET, MASS.- On an island where the average home sale topped $4 million last year, Ginger Andrews’ scallop shanty is a golden ticket.

If she had any inclination, Andrews, a fourth-generation resident of Nantucket, could sell the waterfront structure next week for a life-changing amount of money. The prospect is intoxicating — at least to some of her acquaintances.

“They’ll say, ‘You could have a chef!’” Andrews said. “‘Or, ‘Don’t you want to travel around the world?’”

But she has a different goal: defending her weatherworn, 19th-century shack against buyers who would gut its unadorned interior, install modern layouts and luxuries, and erase a gritty heritage that has already mostly vanished from the island, 30 miles off the Massachusetts coast.

With no children to pass the property on to, Andrews has turned to a little-known legal maneuver that is having a moment on Nantucket and elsewhere in New England. She is attaching a preservation restriction to her property deed, requiring that any future owner retain the structure’s essential characteristics. She also intends to ensure that scallopers, who have long shucked their catch in its narrow kitchen, can continue using the building, the last working scallop shanty on Old North Wharf.

“It’s my way of looking at the tide of development here and saying, ‘Stop,’” Andrews, 69, said, standing in the bare-bones kitchen one morning last month as a tiny space heater cranked against the chill. “It’s the last vestige of the working waterfront.”

To the tourists who swarm its wide brick sidewalks and cobblestone streets every summer, Nantucket looks like a stunningly complete time capsule, dense with pristine examples of colonial and federal architecture. Elegant mansions built by 19th-century whaling captains give way to warm brick storefronts, lovingly restored. The public library, with its towering white columns, is a masterpiece of the Greek Revival style.

Behind the picture-perfect exteriors, though, a steady erosion of history has been underway for years, preservationists say, as ultrawealthy newcomers have remade the interiors of antique houses, wiping out centuries-old walls, staircases, fireplaces, doors and windows.

The trend first raised alarms in 2000, when the National Trust for Historic Preservation named Nantucket one of the country’s most endangered historic places. It cited the demolition of old structures, the removal of original interiors, and new construction that wasn’t in keeping with the island’s character.

While all of Nantucket is included on the National Register of Historic Places — the country’s largest listing, encompassing 5,000 structures — local officials have the authority to protect only building exteriors. As more owners have sacrificed original interiors in favor of new floor plans and amenities, more longtime residents are considering preservation restrictions as a last-ditch means of holding onto history.

After the addition of roughly one new restricted deed each year for the last two decades, the island now has five pending, said Mary Bergman, director of the Nantucket Preservation Trust, which manages the deed restriction program. A similar regional effort, run by the nonprofit group Historic New England, last year added six homes in four states to its roster of 125 protected properties, tying its previous record, said Carissa Demore, the organization’s team leader for preservation services.

The numbers are small, but they may reflect evolving attitudes, preservation leaders said.

“Eventually, the old house, with its integrity and authenticity, will be the rarer thing, and maybe the more desirable thing,” Bergman said. “There is something deeply appealing about keeping something real, and that seems to be increasingly important to younger people raised in a digital age.”

Philip Carpenter, 74, a retired builder, grew up with an appreciation for old things. His father, an antiques dealer, and his mother, a collector, bought a house on Fair Street in Nantucket in 1962 for $12,000, he said, and carefully guarded its original features. With its five fireplaces, its interior wooden shutters and its classic Greek Revival staircase carvings, it remains “remarkably unmolested” nearly two centuries after it was built, he said.

After watching numerous new neighbors gut the interiors of their historic homes, and grieving each time, Carpenter said he had no doubts about attaching a preservation restriction to the house he inherited from his parents — even after friends who work in real estate warned him it would diminish the property’s value.

“There are more important things than money,” he said, “and we’re losing that sensibility.”

Peter Dorsey, a real estate broker specializing in antique houses north of Boston, said a deed restriction could enhance a home’s value for the right buyer, by guaranteeing its historic significance. “It complicates things in a good way,” he said, “because it ensures the buyers are the right people.”

Like Carpenter, Andrews is grateful to older family members for teaching her the value of the past. Her grandfather, a Nantucket fisherman, bought the gray-shingled shack perched above the harbor around 1906. Andrews learned to shuck scallops there, and played “king of the hill” on the mound of discarded shells outside.

By the time she inherited the building in 2000, the wooden pilings it stands on were rotting and sinking. As she shored it up — renting space to scallopers who shucked their catch there — the surrounding wharf was changing fast. Other old waterfront buildings sold for millions, morphing into luxury cabins with coveted boat slips.

Receiving visitors on a still, sunlit winter day, Andrews said she hoped to turn her shanty into a museum of the working waterfront — with working scallopers as one of the attractions.

In the kitchen, where orange rubber aprons hang on hooks by the wooden-latched front door, she described the art of scallop shucking with infectious zeal.

Not that scallop fishing is romantic. “It’s hard work in the cold,” said Andrews, an ornithologist, artist and writer who fished in her youth. “You have to resign yourself to snot falling down your face all day.”

Of course, the island’s sky-high housing costs have endangered more than just historic architecture. Year-round residents, including fishermen, laborers and town employees, have struggled to stay on the island, a problem that feels more pressing to many than preserving antique houses.

As the housing crisis has intensified across the country, more preservationists have sought to collaborate with housing advocates, including on Nantucket. There, leaders plan to purchase a historically protected former lifesaving station to use for workforce housing, and a “house recycling” program relocates and reuses older homes that have been slated for demolition.

Michela Murphy, vice chair of the historic district commission in Provincetown, another high-priced resort at the tip of Cape Cod, sees the two goals as inseparable.

“Our job is not only to protect the structures, but the culture and the way of life,” she said. “If we can’t house our workers, the people who keep the town running, we end up with a place that’s unsustainable.”

Keenly aware of the need on Nantucket, Andrews said she has made plans to hand off the house she lives in, a 300-year-old property passed down through her family, for use as affordable housing after she’s gone.

At a cost of $5,000 to $20,000 for each easement, much of it going to pay lawyers, safeguarding history is not cheap. The Nantucket Preservation Trust polices the deed restrictions once they are in place, hiring experts to inspect protected properties yearly to ensure that no disallowed changes have been made. Thanks to successful fundraising, the trust is prepared to go to court should anyone attempt a prohibited construction project.

Four years after Carpenter initiated the restriction on his Nantucket house, the legal agreement has cleared state review and is awaiting approval by the town. He said he had opted for “draconian” measures, barring future owners from installing insulation or replacing original clapboards.

(Updates to the kitchen and bathrooms will be permitted, as they are in most such agreements.)

His three adult children, who will inherit the property, were not entirely thrilled by his decision, Carpenter said, “but it’s nonnegotiable.”

When the legal documents are signed, he expects to feel a great relief.

“I’ll feel like I’m leaving the legacy I want to leave,” he said. “It’s a beautiful, old summer house, and that’s what it will be.”

This article originally appeared in The New York Times.