By Rebecca Picciotto

New York City Mayor Zohran Mamdani wants to revive one of the most complicated and expensive developments in the city's history: transforming a 180-acre rail yard into the city's biggest affordable housing project in half a century.

The development at Sunnyside Yard in Queens would include 12,000 housing units along with parks, childcare, hospitals and other infrastructure, Mamdani said at a Friday press conference.

He's asking President Trump for $21 billion to do it. Even that much money might not be enough to get it done.

A 2020 master plan proposed building a $14.4 billion deck above the trains to anchor 12,000 apartments, along with office, industrial and retail space.

The plan was ultimately put on hold due to the pandemic. But even before that, city officials knew that getting it done would require extraordinary feats of physical, economic and political engineering. Construction and labor costs have gone up since then, too.

"It's an incredibly complex project," said Alicia Glen, who helped spearhead the project under Mayor Bill de Blasio and now runs her own development firm. "It could be done in a decade, but that's really optimistic."

The mayor is hoping that Trump -- himself a developer from Queens -- can help him out. During a surprise Thursday meeting at the White House, Mamdani tried to convince the president to pledge the funds. Trump didn't formally commit to the investment, but Mamdani said he was interested.

"We will continue to talk about this proposal," Mamdani said Friday. "It is going to be a long process."

The Sunnyside Yard redevelopment has already been long drawn out. For more than a decade, city officials have been contending with logistical hurdles to turn the busiest passenger rail hub in North America into an entirely new neighborhood.

To start, the elevated deck could be built on only about 80% of the site because of the busy train activity, according to a feasibility study released in 2017.

The land's topography is also challenging. Train tracks are spaced unevenly, and it would be hard to build very tall properties. But the overhead deck itself would have to be tall to accommodate the yard's electrical wiring.

"These are the physical challenges Mamdani is going to have to overcome, " said Kate Wittels, who helped conduct the feasibility study and is now a partner at consulting firm HR&A Advisors.

Then, there is the financing. The master plan doesn't set out to pay for itself -- the project would require a major public subsidy. That became a hurdle for the de Blasio-era plan. That administration had a fraught relationship with the federal government during Trump's first term, which made it difficult to secure federal assistance.

"At the time, we were like, 'Well, we don't have a cooperative federal partner and it's going to be very difficult to do this without a federal partner,'" said Glen.

Mamdani's relationship with Trump has remained civil, if not friendly. In the Oval Office on Thursday, the two New Yorkers posed for a picture together where Trump beamed, holding up a mock-up front page of the New York Daily News that Mamdani made for him. It read: "Trump to City: Let's Build."

If Trump follows through on the $21 billion investment, it is unclear how far that money would stretch. The estimated costs in the 2020 master plan have likely changed due to rising prices for materials and construction labor.

The local planning of the project is a maze of competing interests. Much of the site is owned by Amtrak, a corporation chartered by the federal government. The city and the Metropolitan Transportation Authority, which is controlled by the state of New York, also own portions of it. Coordinating the interests of these different owners, along with the surrounding neighborhoods, could pose political hurdles.

Mamdani's biggest edge over the initial Sunnyside Yard proposal may be the changing politics around housing development. When Sunnyside Yard was put forward in 2020, It was difficult to garner community support for a giant master-planned development in the middle of Queens.

Rep. Alexandria Ocasio-Cortez (D., N.Y.) stepped down from the Sunnyside Yard steering board because of her constituents' complaints about the project.

But as voter frustration grows over rising housing costs, public sentiment has shifted towards building homes. Mamdani himself campaigned on boosting housing development as a way to address the city's dire shortage of homes.

"Nimbyism was stopping us from being able to build," said Annemarie Gray, who served at the New York City Economic Development Corporation when the Sunnyside Yard project was in the works. "Mamdani is revisiting this project in a very different political environment."

Write to Rebecca Picciotto at Rebecca.Picciotto@wsj.com

(END) Dow Jones Newswires

February 27, 2026 17:14 ET (22:14 GMT)

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