In a proposal that’s likely several years away from construction, Borough President Ruben Diaz Jr. unveiled his vision for more development by plating over existing open air rail yards peppered around the borough.

The prospect of plating the yards served as the crux to his 10-page report on the promise three rail yards hold for mixed-use development. And while two yards in the Concourse and Riverdale sections of the Bronx would work as pragmatic sites, Diaz zeroed in on the Concourse Yard, a breathtaking industrial span in Bedford Park, as having “tremendous potential” for development built above the tracks. The yard, found at 205th Street and Bedford Park Boulevard, houses the B, D and 4 subway lines, taking up 19 acres, though 13 acres of it would be plated for roughly 2 million square feet of “new real estate.”

The Concourse Yard’s potential for re-configuration is derived mostly from its surrounding amenities. It’s not only home to these subway lines, but also to schools and nearby hospitals. It’s also closest to the Kingsbridge Armory, set to be converted into the Kingsbridge National Ice Center.

“New real estate where we won’t be displacing folks; new real estate where we could have commercial, residential, retail and the potential for expansion of Lehman College,” said Diaz, delivering remarks on Feb. 3 at Lehman College on Bedford Park Boulevard, which abuts the yards.

Diaz made his intentions for platform development known during his State of the Borough speech last year. Since then he has scheduled meetings with the borough’s elected officials on the likelihood this proposal can be championed. “We know that it’s worked in other parts of the city,” he said. “So why not look at the Bronx?”

But it’s also home to Scott Tower and Tracey Towers, two separate complexes that’s home to thousands of residents.

Barbara Stronczer, president of the Bedford Mosholu Community Association, whose borders include the Concourse Yards, remained on the fence on seeing this project through, given its proximity to current residential buildings. “My feeling is you have Scott Tower and you have Tracey Towers,” said Stronczer. “They’re not going to be happy when they hear this, but we’ll see.”

Still, the proposal has won the fervor of Assemblyman Jeffrey Dinowitz, whose district overlaps with the yards. “I’m very bullish on this,” said Dinowitz. “I actually proposed many years ago to the then school superintendent of schools in our district the idea of building schools there because District 10 was extremely overcrowded.”

Dinowitz envisioned part of the platform space to house Lehman College’s new parking facility as a way to replace the current lot that sits just near the Jerome Park Reservoir. “I want that area where the parking is, and it’s a substantial bit of land on Goulden Avenue, turned into parkland,” said Dinowitz.

While the report is high on vision, it’s light on mechanical engineering, the neighborhood’s environmental impact, and any level of endorsement from the Metropolitan Transportation Authority, which owns the property.

“It is still feasible as a project, but much, much more challenging,” said George Deodatis, Ph.D., a professor of civil engineering at Columbia University. “The columns and the foundations will have to be much larger. Depending on the current configuration of the rail tracks, some of them might have to be permanently removed. A lot will depend on the quality of the soils at this particular location.”

Diaz admitted that the Authority “did not say that they support this, but I am comfortable in my many years with dealing with the MTA that they did not say, ‘no way, no how.’” “We’ll take that for now. It’s the most positive they could be at this moment,” he said.

The MTA sidestepped any hint at a commitment. Through spokesman Kevin Ortiz, the MTA simply said it has “communicated with the BP and we look forward to studying his report.”

Some can look at the proposal as a rehash of an idea that was once batted around the Bronx, though money has always kept the project from ever becoming a reality. But building above rail yards is an old concept that’s finally been taking off these days given the demand for more housing across the city.

One of the more successful plating projects to date is Hudson Yards, a mixed-use development site on Manhattan’s west side. Headed by conglomerate The Related Companies, the site includes offices, retail space and housing. Construction began in 2010 after Oxford Properties Group agreed to build a platform over the West Side Yards for $400 million. Related, under a deal first drafted under original developer Tishman Speyer, agreed to pay the MTA $1 billion in air rights in exchange for a 99-year lease.

The more pressing rail yards project these days is at the Sunnyside Yards in Astoria, Queens, where the New York City Economic Development Corporation is assessing proposals that would deck the near 200-acre open yard. It’s the latest proposal in a long line of bids that have fizzled since the 1960s.

This observation stirred one reporter to ask whether this project could take off by the time Diaz’s term expires in 2018. “All we could do is get it started, and hopefully with the next administration, be it the Bronx administration or the city’s administration, hopefully there will be that level of enthusiasm and that level of commitment to finish what was started,” said Diaz.

Construction of the project is estimated between $350 and $500 million, and would require a public review process involving Community Board 7 and the New York City Council.