When Adele and Mark Foster bought their home on the Mandeville lakefront in 2006, neighbor Suzie Hennessey promised the couple that the Rest A While property next door, a longtime retreat center with buildings dating to the 1850s, would never be sold.

Hennessey was president of the Louisiana chapter of the International Order of the King’s http://www.iokds.org/ttp://">Daughters and Sons, which had owned the site since it was donated to the group in 1905 and turned into a place where orphans and widows from New Orleans could go to enjoy the beauty of the lakefront.

She told Adele Foster she had turned down a $2 million offer to buy the Lakeshore Drive property and was determined to see it continue as a site for spiritual renewal.

But Rest A While did end up being sold to developer Barrett McGuire for $750,000 a year ago. Now neighbors like the Fosters and preservationists are worried about what will happen to the last remaining hotel from an era when Mandeville’s lakefront was a playground for wealthy New Orleanians.

McGuire said last week that he didn’t know when he bought Rest A While exactly what he would do with the site, which has three historic buildings: the former Frapart Hotel and two smaller buildings, Hadden Cottage and the Sophie B. Wright Cottage. As a resident of Lakeshore Drive himself, he said, his main objective is to ensure that the site is preserved.

Now, a year later, McGuire said he has put time, money and effort into making sure that the buildings are sound and remain true to their original architecture. But his plans for the property remain something of a question mark.

The latest idea — a restaurant and lounge in the former Frapart Hotel and wine bars in the cottages — will go before the Mandeville Planning and Zoning Commission on Jan. 13.

That plan has touched off strong objections from the Fosters, who worry about the noise, smells and other ills they fear will come from having a commercial kitchen and Dumpster near their house.

McGuire’s previous idea for the property — building assisted-living condominiums in the rear of the property and using the historic main structure as a communal dining hall — also generated controversy.

Nearby resident David Persons said neighbors had a lot of problems with that plan and questioned the wisdom of moving elderly people into a flood plain and requiring them to walk from condos to the dining hall.

Foster, one of the founders of the Old Mandeville Historic Association, said she initially thought turning the site into a place for elderly residents was in keeping with http://www.oldmandevillehistoricassociation.org/Newsletter.html://">Rest A While’s history. But she began to have reservations when she learned McGuire planned to rent the units rather than sell them and didn’t seem to have plans for an age limit on who could live there.

Then, late last month, she learned that he was seeking a permit for a restaurant and bars.

McGuire said he tabled the retirement home idea after what he described as “quite a bit of opposition” from neighbors. He said his desire to preserve the property is a labor of love.

The lakefront is a mixed-use area, he pointed out, and the property had a commercial life before it was a retreat center. But he said he believes that he and his neighbors will “find a way to work together.”

Mandeville Councilman Ernest Burguieres said he can see both sides of the issue: the developer’s need to make his investment profitable and the neighborhood’s concern about the fate of a historic gem.

Buying a historic property has some advantages but also presents challenges, Burguieres said, and he doesn’t know how viable a restaurant at the site would be, given the experience of other eating establishments in the area.

But what the Fosters and Persons want for Rest A While is a new owner: specifically, the city of Mandeville.

Ironically, that’s an idea that McGuire’s father, former Mandeville Councilman Jack McGuire, had urged in a 2011 letter to Mandeville Mayor Donald Villere, calling the old hotel the last survivor of Mandeville’s golden age.

A group of neighbors is paying for an appraisal that will determine the value of the entire property as well as the value of just the front half and just the back. The developer has offered to pay half the cost of that appraisal, Foster said, and that makes her think he might be willing to sell.

Villere doesn’t rule out the possibility that the city could purchase Rest A While, but he called talk of buying “a little early,’’ noting that there are still hearings ahead and that the developer is still figuring out what he wants to do.

Foster contends that the lakefront should be a priority for such acquisitions: It’s where people go for recreation, she said, calling it Mandeville’s French Quarter.

Her husband, Mark, blasted the developer’s plans in an email to city officials.

“Mr. McGuire is trying to fit a square peg into a round hole,” he wrote. “The Rest A While property has a unique physical and historical position in the neighborhood. The buildings can’t be demolished, so Mr. McGuire is forced to incorporate them into his plans, which seem to change weekly in an effort to get something, anything approved. It seems when the investor’s only priority is maximum return on investment, what is best for the neighborhood and the historical property at hand, is out the window … it’s not good for my home, the neighborhood or Old Mandeville.”

Follow Sara Pagones on Twitter, @spagonesadvocat.