Affordable housing construction has been stifled by the designation of properties and entire neighborhoods as protected historic landmarks, argues a report released by a real estate industry group Tuesday.

An analysis shows that of the 35,000 affordable units created over a 10-year period, only about 100 were built on landmarked properties, says the report from the Real Estate Board of New York.

And while less than 4% of the city has been landmarked, the report argues that policymakers should take a "serious look" at the barriers to building on landmarked properties to meet the demands for affordable housing.

Andrew Berman, the executive director of the Greenwich Village Society for Historic Preservation, questioned the findings.

"The notion that historic districts are making New York City unaffordable is ludicrous," he said.

Instead, he points to the disappearance of affordable housing throughout the city as a much greater threat. "The affordable housing we have has been disappearing at an incredible pace," he said.