Hours after a judge ruled that the city can go ahead with a controversial slate of school closure and openings, union lawyers are starting to sketch out their response.

Department of Education officials said construction projects planned to ready school buildings for co-locations were free to begin. At PS 308 in the Bedford-Stuyvesant section of Brooklyn, workers were painting classrooms. But Rafiq Kalam Id-Din said he was still waiting for the city to approve construction for the school he runs, Teaching Firms of America Charter School.

Meanwhile, lawyers for the United Federation of Teachers, one of the leading plaintiffs in the lawsuit, are studying the decision and deliberating their next steps. The ruling last night denied a preliminary injunction that would have barred the city from moving forward with its plans, but it did not assess the merits of the UFT and NAACP’s claims that the city’s plans would lead to inequities among schools.

Last night, the union said it would not drop the lawsuit, and any future adjudication would focus on those equity claims. But it could take some time for union lawyers to wade through questions that could influence how they proceed.

One question is just what the union would seek to get out of such a suit. With the start of the school year just weeks away, the chance of any further action preventing the start of phase-outs and the beginning of co-locations is virtually nil.Reversing those actions once they start would be very difficult. But the plaintiffs could instead seek a form of redress that deals with underlying equity issues in the DOE’s planning without affecting individual schools.

Figuring out the goals of continued litigation requires consultation with the NAACP and the host of other plaintiffs who signed onto the suit before it was filed in May. That consultation is likely to take some time, especially because there some of the plaintiffs are likely to be away during the summer vacation. UFT President Michael Mulgrew, for example, is in South Africa right now, where he is attending an international convention of teachers union officials in Cape Town.

When the lawyers do reach all the plaintiffs, they could face some reticence to press on now that its clear the case won’t be easy to win. Schools Chancellor Dennis Walcott and charter school advocates have called on the union and NAACP to drop the suit, and the higher stakes of continued action, which could ask for the city to undo its plans, not just halt them, might be too much for some of the lawsuit’s original supporters.

Finally, there’s an open question about who would hear the lawsuit. While there’s no assurance, it could be Judge Paul Feinman, the same State Supreme Court justice who denied the preliminary injunction. That would give the UFT — and the city — an indication of what to emphasize in court. In yesterday’s decision, Feinman said that the equity issues “do not lean inexorably in the direction of either party,” but he also said that it might well be true that the city’s educational policies are misguided.