The Princeton Battlefield Society will appeal a Mercer County judge’s rejection of its most recent attempt to keep the Institute for Advanced Study from building faculty housing on land owned by the Institute that the Battlefield Society says is historic and should not be disturbed.

Attorney Bruce Afran, representing the Battlefield Society, said Judge Mary Jacobson’s ruling last Friday was not unexpected. “These cases are really resolved in appellate court, so everybody expected this to have to go to a higher level,” he said on Monday.

Judge Jacobson’s decision upheld the approval that Princeton’s Planning Board gave the Institute last year for an amended version of the project, which had first been approved in 2012. The IAS wants to build 15 units, clustering eight townhouses and seven single-family dwellings on a seven-acre parcel. The Battlefield Society says the houses would be on land where American and British soldiers fought during the Revolutionary War in 1777.

The Delaware & Raritan Canal Commission blocked the project in 2012 because of its encroachment on a stream corridor, and the IAS tweaked the plans to slightly shrink the footprint. It was that amended application that the Planning Board approved last year. The Battlefield Society said that because of the amendments, the project is essentially new and the IAS should have to start over. The Planning Board did not agree, and Judge Jacobson concurred.

As part of the ruling, Judge Jacobson issued a temporary delay on any start of construction to allow time for the Battlefield Society to appeal.

“We respect Judge Jacobson’s opinion, but we do not believe she’s correct,” Mr. Afran said. “And we believe there are serious failings in what the Planning Board did three years ago and again [in 2010]. They refused to hear relevant evidence. This decision is an error and it ignores all of the duties of the Planning Board to protect historical sites.”

The Institute issued the following statement: “The Institute for Advanced Study is very pleased with Judge Jacobson’s decision to uphold the Princeton Planning Board’s approval of our amended plan for Faculty housing and we look forward to moving ahead with the project.”