A group calling itself the Friends of the Motherhouse is suing the city of Portland over a zoning change given to a developer looking to build senior housing on Stevens Avenue.

The group and two individuals, Barbara Weed and Raymond Foote, want to reverse the City Council’s decision in July to rezone 12 acres that include the historic Sisters of Mercy Motherhouse and athletic fields used by Catherine McAuley High School. The land was changed from a low-density residential zone for single-family and smaller multi-family homes into a higher-density zone that would allow nearly 250 units of housing.

“I’m shocked at the proposed density for that land,” Foote said. “The City Council is out of touch with the citizenry. With the July 6 vote, the council sold the soul of a great neighborhood. Deering Center is a gem and (overly dense) building risks destroying the very quality that makes it such a prized and much-loved area of the city.”

City Manager Jon Jennings said the lawsuit was unfortunate, since the proposal was reviewed extensively by staff and councilors, and the developers willingly scaled back their proposal in response to neighborhood concerns.

“This is simply an effort to delay the project after a robust community process,” Jennings said.

The lawsuit, filed on Oct. 22, 2015, comes as the city is undergoing going a housing crisis, prompting it to look for ways to increase its housing stock, and is the latest example of how strongly longtime residents feel about preserving the character of their neighborhoods. In recent years, a group of Munjoy Hill residents organized and advocated for an unsuccessful ballot measure to undo a zoning change granted to 58 Fore St. on the eastern waterfront. And West End residents prevailed in Superior Court challenging a zoning change that allowed an office use at the Williston-West Church, although they ultimately lost in the Maine Supreme Judicial Court.

Deering Center is a quaint neighborhood defined mostly by single-family homes and tree-lined streets. Small businesses and schools – such as Deering High School, Longfellow Elementary School and the University of New England – line Stevens Avenue, the neighbor’s major thoroughfare. The area also includes two of the city’s largest open spaces in Evergreen Cemetery and Baxter Woods, a 30-acre nature preserve.

The neighborhood is home to about 4,060 people, or 6.1 percent of the city’s population of 66,000. It’s one of the city’s oldest, wealthiest and whitest neighborhoods. Nearly 17 percent of neighborhood residents are age 65 or older, and the $56,000 median income of its residents is higher than the citywide median of $46,000.

Sea Coast Management and the Developers Collaborative are planning on restoring the Motherhouse, originally built in 1908, and converting it into 88 units of senior housing. Additional residential buildings up to 55 feet tall could be added near the rear of the property located at 605 Stevens Ave.

The Friends of the Motherhouse group claims that the city didn’t follow proper procedures in granting the zoning change and that the new zoning doesn’t comply with the city’s Comprehensive Plan, which guides land use decisions.

David Lourie, the attorney who is representing the plaintiffs, said the change is not in harmony with the surrounding neighborhood.

The two sides will meet on Feb. 3 for a court-ordered mediation.

“There’s no chance of success on mediation as far as I can see,” said Lourie, who worked as a Portland city attorney from 1975 to 1991.

City Hall Spokeswoman Jessica Grondin said the lawsuit is based on a misreading of the city’s Comprehensive Plan. “We believe the lawsuit is without merit and the rezoning is consistent with the Comprehensive Plan,” she said.

The proposed development of senior housing drew strong neighborhood opposition when it was first proposed last February. Neighbors organized a group called Preserve Deering Neighborhood to fight the proposal and showed up in force to speak against the zone change, showing councilors a large scroll of signatures.

The council last June delayed a vote on the zone change to allow Sea Coast Management and the Developer’s Collaborative time to meet with opponents. The result was a compromise, where the development team eliminated 85 units of housing. The council later voted unanimously to approve the change.

Foote, one of the plaintiffs, is concerned about the loss of the athletic fields and the impact the development could have on Baxter Woods and its recreation trails. The 63-year-old Deering Center resident said he has been going to the park since he was a young boy.

Kevin Bunker of the Developers Collaborative said the development team, which isn’t named in the lawsuit, will intervene in an effort to get the case dismissed. He said that efforts to meet with the plaintiffs have been unsuccessful, and that the lawsuit could prevent the project from starting this spring as planned.

“It could slow us down and make life difficult,” Bunker said. “We don’t know what their goals are because they won’t meet with us.”