A five-judge appellate panel put the brakes Thursday on NYCHA’s plan to demolish and rebuild 2,000 public housing apartments in Chelsea, handing a significant legal victory to tenants who have spent months fighting one of the most sweeping public housing redevelopment projects in the city’s recent history.

The Appellate Division issued a stay on the project while the court weighs a lawsuit arguing that NYCHA and its private partners, the Related Companies and Essence LLC, bypassed required regulatory review. A hearing is set for May 19, and a final decision would likely come months after that, pushing any construction activity well into the summer at the earliest.

The project was originally supposed to begin last December. It has not.

The plan calls for demolishing 18 deteriorating buildings across the Fulton, Elliott, and Chelsea Houses complexes, then rebuilding six taller towers for current residents. From there, nine additional buildings would go up, housing 900 affordable units and 2,500 market-rate apartments. The revenue generated by those market-rate units would finance the entire reconstruction effort, a financing model that has drawn criticism from tenant advocates who see it as privatization dressed up as renewal.

The May hearing will center on arguments from tenants and former state Sen. Tom Duane that the project violates federal housing law and was fast-tracked without the governmental review typically required when private developers seek zoning changes. If the court sides with those plaintiffs, the consequences could be severe for the whole venture.

Attorney Thomas Hillgardner, who filed a separate lawsuit last week, put it plainly. “Should the Duane plaintiffs prevail, it seems likely that the entire plan will need to be withdrawn and Related and NYCHA will have to go back to the drawing board,” he said.

Hillgardner’s own lawsuit targets a specific and troubling element of the project: the treatment of 18 elderly residents at the seniors-only Chelsea Addition. Those tenants have refused to relocate, a required first step before demolition can proceed. His lawsuit accuses NYCHA, Related, and Essence of illegally harassing those residents to force them out, knowing they would also face a second relocation once a replacement building is completed three years later.

Forcing elderly public housing residents to move twice, Hillgardner said, has caused them serious anxiety. He predicted that if the Duane lawsuit succeeds, NYCHA and Related would have to abandon the current relocation structure entirely.

NYCHA spokesperson Michael Horgan responded to the ruling with a statement that offered little beyond the procedural: “The Court granted a stay pending the appeal, and we will await the Court’s final decision after consideration of the full appeal and following argument.”

That kind of response is what you get when an agency knows it’s in a difficult spot legally and has nothing reassuring to say publicly.

What’s happening in Chelsea fits a pattern New Yorkers should recognize by now. A public housing complex sits on valuable land in a neighborhood where market-rate rents run sky-high. A private developer partners with the city, promising to fix the housing while also building luxury units. The financing math only works if those luxury units generate serious returns. And residents, many of them elderly and low-income, get caught in the middle, told to trust a process that has every incentive to prioritize the balance sheet over their stability.

The Chelsea Addition tenants are not an abstraction. They are 18 older New Yorkers who built lives in that neighborhood, who were not given a meaningful choice in any of this, and who are now being asked to uproot themselves twice so that the numbers can work out for Related Companies.

The appeals court’s pause does not resolve anything. It buys time, and time matters. A hearing in May, a decision sometime after that, months more of uncertainty for thousands of NYCHA residents whose apartments have been deteriorating for years. None of this is a good outcome. It is, at best, a check on a process that moved too fast and cut too many corners.

Related and NYCHA got their ambitious plan. The courts may now force them to actually justify it.