Opponents of the Atlantic Yards development project in Brooklyn are focusing on a new way to hem in the $4 billion development project: the landmark protection process.

The city’s Landmarks Preservation Commission is holding a hearing tomorrow to “calendar” a proposed historic district for the Prospect Heights neighborhood, the first significant step needed for the area to receive the protected historic district status.

While none of the footprint of the current Atlantic Yards project would be affected by the proposed designation, it would create a surrounding area that could hinder further expansion.

The Atlantic Yards developer, Forest City Ratner Companies, is seeking to build 16 skyscrapers, an 18,000-seat basketball arena for the Nets, and thousands of apartments at a site at the corner of Flatbush and Atlantic avenues.

“What it would do is serve as a buffer against Atlantic Yards and halt other construction in the area that is out of scale,” the City Council member who represents the area, Letitia James, who has been pushing the designation for a number of years, said in an interview yesterday.

The Municipal Arts Society, the group organizing the legal opposition to the Atlantic Yards project, the opposition group Develop Don’t Destroy Brooklyn, and the Prospect Heights Neighborhood Development Council are applauding the city’s move for historic designation.

“The pressure from the Atlantic Yards project and other recent developments are of grave concern to the hundreds of local residents who have written in support of historic designation for Prospect Heights,” the Municipal Arts Society said in a statement.

The process of “calendaring” assigns buildings to the Department of Buildings database, and any work on a designated building that requires a permit would then need to be reviewed by the Landmarks Preservation Commission prior to the permit being issued.

The proposal would include portions of the area bordered by Flatbush and Washington avenues and between Atlantic Avenue and the Eastern Parkway.

A public hearing on the designation would likely occur in the fall.

The area’s signature structures are 19th- and early-20th-century houses.

A spokesman for Forest City Ratner was unavailable for comment yesterday.

The landmarks commission tomorrow will also be discussing a designation of West Chelsea that would create another historic district just south of the West Side Rail Yards — the site of another multibillion-dollar development project.

The executive director of the historic districts council, Simeon Bankoff, said the trend of designating historic districts adjacent to large developments may stem from resident concerns that megaprojects may not live up to their potential.