The city’s ambitious proposal to deck over the exposed rail yards in Sunnyside to create a platform for parks, schools, retail, and thousands of new apartments has a master planner, according to several sources familiar with the project.

Crain’s reports that Practice for Architecture and Urbanism (PAU), the studio founded by former SHoP Architects partner Vishaan Chakrabarti, has been tapped through a request for proposals to conceptualize what the Queens megaproject could look like. PAU declined to comment and the city’s Economic Development Corporation (NYCEDC), who issued the request for proposals in November, told Crain’s that it has not officially designated a team.

The idea to develop the site is not a new one: Mayor de Blasio proposed the project at his state of the city address in early 2015, and a feasibility study followed. The findings of that study were released in February 2017.

The study found that about 80 to 85 percent of the 180-acre site is buildable with the use of decking. The leading proposal put forth in the study would see the creation of between 18,000 and 24,000 apartments, of which about 30 percent would be earmarked as affordable housing.

That proposal would also create between 13 and 19 schools, 38 and 52 acres of open space, and retail. The cost of the whole shebang would be on par with the cost of Related Companies’ Hudson Yards, at around $19 billion.

That plan, of course, is all conceptual. PAU’s task now is to build off of the city’s proposal and hash out a more specific plan for how the space can be used. The process may take up to two years.

“We remain on track with the original schedule for this project,” a spokesman for the NYCEDC said in a statement issued to Crain’s. “We continue to work closely with Amtrak, and we will also engage community stakeholders before beginning any master-planning process.”