Two trade groups and the New York City Dept. of Buildings (DOB) are scheduled to give oral arguments on Dec. 17 before a state judge in a case involving the prefabricated building units of Atlantic Yards' B2 tower.

A factory at the Brooklyn Navy Yard is making the units for developer Forest City Ratner Cos.' $117-million modular high-rise, the first residential tower at the Atlantic Yards site. But the trade groups—Mechanical Contractors Association of New York (MCANY) and the Plumbing Foundation City of New York (PFCNY)—charge that the prefab work is being done without licensed trades people and sued DOB in July.

Work on the units should not be conducted off-site and without supervision of DOB-licensed master plumbers and fire suppression contractors, says Stewart O'Brien, PFCNY executive director. Allowing such work violates the NYC construction code, he says.

A DOB spokeswoman says the agency has no comment at this time.

"Our argument is not with Forest City Ratner; it is with the city," Stewart says. "The [construction] code says one thing but, rather than getting the code changed, [DOB] allowed fire suppression and plumbing and gas work without using licensed individuals as required by the code."

Stewart adds that MCANY and PFCNY are in favor of modular construction as a means to save construction costs. "What we don't understand is why you would want the safety work, including gas work, to be done in the factory by unlicensed individuals when the rate that they are paying those unlicensed individuals is the same that it costs for licensed personnel," he says.

Justice Eileen A. Rakower of the state Supreme Court, New York County, is assigned to hear the oral arguments.

Meanwhile, the factory is expected to begin shipping the finished modules to the B2 site in January. FCRC announced in its quarterly earnings report last September that the tower is expected to open in the fourth quarter of 2014.