The Peconic Land Trust this week put up for sale a Sagaponack farmhouse that has been the focus of debate in the past year over historic and land preservation.

The house, and the one-acre parcel it sits on, are listed at $2.5 million. If it sells the house, the Land Trust says it will use the proceeds to preserve more farmland in Sagaponack.

“There have been people interested in this house from the very beginning,” Peconic Land Trust President John v.H. Halsey said of the approximately 1,900-square-foot house. “The person who buys it will know that there are some limitations on what they can do with it. But they want it for what it is, and that’s nice. They like the idea of an 80-year old farmhouse in its original setting.”

The setting is not quite original. The house spent the first eight decades of its life about 600 feet to the east of where it sits on Hedges Lane now but traveled a long road to get where it is now.

Built in the 1930s by Sagaponack native Wallace Hildreth, the house and another smaller, older former residence on the former farmstead had sat empty before builder Michael Davis proposed tearing them down in 2009 to make way for a new subdivision.

Residents objected to those plans and protested at village historic preservation board meetings, calling both houses a part of Sagaponack’s history and spirit. Mr. Davis relented and offered to restore the older structure and incorporate it into his building plans. He said he would hold off demolishing the other house—referred to as the “four-square,” for its simple design style—but that it would have to be removed from his land if it was to be saved. The Peconic Land Trust stepped in and agreed to take ownership of the house and, under an agreement with the board of a private land foundation, move the house to an 11-acre farm. Just as quickly as proponents for saving the house appeared, so did opponents of the move, claiming the trust and the Peconic Land Foundation, which owns the farmland, were abusing their positions and missions.

Last spring, the house was nonetheless placed on a one-acre portion of the field that is left fallow each year. But when a neighbor sued and the farmer who works the land said losing that portion of the property would disrupt his operations, the house was moved to another corner of the property, one that affords a sprawling farm vista but means the loss of an acre of farmland—counter to the Peconic Land Trust’s founding principles.

But Mr. Halsey has argued that the millions from the sale of the property—a subdivision application to create the 1-acre parcel for the house and preserve the remaining 10 acres in perpetuity is pending with the Sagaponack Village Planning Board—will allow the trust to protect far more land than it is losing. The money will help complete the $6 million purchase of 7.6 acres of farmland on Sagaponack Main Street, just north of Montauk Highway.

The creation of the building lot carries with it stipulations for the future of the house, since whoever purchases it is expected to want to do significant renovations. Mr. Halsey said the agreement will be that the house can only be expanded by 50 percent, or about 1,000 square feet, leaving a total size much smaller than what would be allowed on most 1-acre parcels in Sagaponack. Any additions also must be made at the rear of the structure, so that the four-square facade will be preserved.

“This has been a marathon effort, over a year, that I guess isn’t over yet,” Mr. Halsey said. “But I think when we get this deal done, assuming—hoping—we get this deal done, I think everyone will be able to see that we did a good thing here for Sagaponack, on two fronts.”