An expansion of Park Tudor School’s campus has put an end to plans for an 11-lot gated housing development just south of 75th Street and College Avenue.

The private school recently bought the 5.7 acres north of its campus that Dr. Bill Nunery, a local ophthalmologist, had planned to develop into an upscale residential enclave known as Grace Hill.

Park Tudor bought the Nunery property and a house adjacent to the campus with $1.5 million in restricted gifts from anonymous donors, said Dr. Matthew Miller, Park Tudor’s head of school, in a statement distributed by the school.

Including the house, which will become a residence for the head of school, the real estate purchases will allow Park Tudor to expand the size of its 56-acre campus by 20 percent.

“We are deeply grateful for the gifts that allow Park Tudor to enlarge its borders,” said Miller, who started at the school July 1.

The school has no immediate plans for the Nunery property. Park Tudor is forming a committee that will spend several months considering what the campus expansion should include. When the committee’s work is finished, Park Tudor’s board of directors and a master planner will use the committee’s findings in developing a comprehensive plan for Park Tudor’s future.

The school’s purchase of the property brings to an abrupt end plans for Grace Hill that appeared to be on track as recently as September. In May, the city approved the plat for the development, allowing the sale of lots—all of which were less than a half acre—for between $325,000 and $395,000.

The wooded lots on undulating terrain were expected to be in big demand in densely populated Washington Township, where new-home sites are rare. Buyers of the lots would have had to abide by certain covenants attached to the property. For example, lot owners would have been required to have their house designs approved by an architectural review committee that was being set up, and construction had to start within a year of closing.

Nunery purchased the property 30 years ago from Park Tudor, which retained right of first refusal if Nunery decided to sell it in the future. His wife, Mathieu, said she and her husband didn't think Park Tudor was going to exercise its right and were within a week of breaking ground to install roads and sewers on the site when the school intervened in September.

She said they could have declined the school’s purchase offer for the entire parcel, but Park Tudor would have had the right to intervene on each individual lot sale.

“We’re disappointed we didn’t get to do Grace Hill as a development, but we’re happy Park Tudor got the land,” she said.

For Park Tudor, the property was its most obvious path to expansion. The school, which has 1,000 students in pre-kindergarten through 12th grade, is hemmed in on the south by 71st Street and on the east by College Avenue. There are houses to the west and northwest of the campus.

The listing agents for the Grace Hill lots, Mark Zukerman and Jeffrey Cohen of Encore Sotheby’s International Realty, didn’t return phone calls seeking comment on the unraveling of the residential plan.