These homes on Park Place between Vanderbilt and Underhill avenues in Prospect Park are part of more than 600 houses now included in the National Register of Historic Places, according to the National Park Service. View Full Caption DNAinfo/Rachel Holliday Smith

PROSPECT HEIGHTS — More than 600 homes and buildings in Prospect Heights are now part of the National Register of Historic Places following an application by a neighborhood group to expand the area’s historic district.

The National Park Service added the 612 properties to the registry Feb. 16, according to an announcement Wednesday by the Prospect Heights Neighborhood Development Council, which applied for the designation last spring.

The new district — which joins about 300 Prospect Heights buildings already included on the National Register — now encompasses a total of 917 properties, mostly 19th-century rowhouses and apartment buildings, along Flatbush, Vanderbilt, Washington and Underhill avenues and many side streets including Bergen Street, St. Marks Avenue and Prospect, Park, Sterling and Butler places, PHNDC said.

“This action by the National Park Service is a reminder that, in the face of tremendous development pressure, Brooklyn’s historic neighborhoods remain a national treasure whose preservation is essential to the borough’s future,” said PHNDC chairman Gib Veconi in a statement.

The designation will allow homeowners in the district to apply for federal tax credits to help with restoration costs. State tax credits are also available, PHNDC said; the same 612 properties were added to the New York State Register of Historic Place in December following a nomination by the state last fall.

PHNDC thanked Councilwoman Laurie Cumbo and the area’s former Councilwoman and current Public Advocate Letitia James, for helping in securing the designation.

Both applauded the district expansion as an “incredible win.”

“These iconic rowhouses have contributed to the culture, history, and beauty of our borough for centuries and it is imperative that we legally protect these building with this designation,” James said in a statement.

For more information about homeowner tax credits and to see a map of the new historic district, visit PHNDC’s website.