November 17, 2011, 12:16 pm
Design Unveiled for Tower at Atlantic Yards
By CHARLES V. BAGLI
The developer Bruce C. Ratner unveiled the design Thursday morning for the world’s tallest prefabricated steel structure, a 32-story residential building at the corner of Flatbush Avenue and Dean Street in the $4.9 billion Atlantic Yards project.
The 350-unit building uses rectangular shapes, colors and glass to break up the mass of the structure, which would sit snugly up against Barclays Center, the new arena of the Nets basketball team that is scheduled to open in September 2012. Mr. Ratner, chief executive of Forest City Ratner, said that prefabrication or modular construction could save time and cut construction costs by as much as 25 percent. Fourteen other residential buildings would be built at Atlantic Yards using the same technology.
Forest City Ratner is also negotiating a labor agreement with construction unions, which have supported Atlantic Yards, but could end up with fewer jobs and lower wages for some workers if the project goes forward.
Mr. Ratner said Thursday that he hoped to begin construction early next year. But the start date has been a moving target for more than a year now. The developer ultimately may instead decide to build the first tower conventionally. But his company has now invested two years in studying modular construction, a technology that has existed for decades, but is largely untested at this height. The world’s tallest modular building is a 25-story dormitory in Wolverhampton, England, that was built in 2010 in fewer than 12 months.
In New York City, the School Construction Authority has used the technology to build classrooms, and Capsys, a modular builder based at the Brooklyn Navy Yard, has built prefabricated, steel-frame housing up to seven stories tall in Brooklyn and on Long Island.
Mr. Ratner said that 60 percent of the construction would take place in a factory, where about 1,000 steel-frame modules would be built and outfitted with electric and plumbing lines, kitchens and bathrooms, while the construction site is excavated. The modules would be taken to the site, lifted into place by crane and bolted together. Steel bracing would rise with the stacked modules.
The challenge for developers, architects and engineers in building taller modular buildings has been to design an economical bracing system that would protect the structure from wind shear and seismic forces. The developer is working with SHoP Architects, Arup structural engineers and XSite Modular. “If anybody can crack the code,” Mr. Ratner said, “this group can.”
But he is also trying to work out an agreement with the construction unions at a project that once promised upwards of 17,000 jobs. Under current wage scales, union workers earn less in a factory than they do on site. A carpenter, for instance, earns $85 an hour in wages and benefits at a construction site, compared with $35 in a factory setting. “We are in the process of attempting to reach an agreement that will work for the building trades and Forest City in an effort to create permanent employment,” said Gary LaBarbera, president of the Building and Construction Trades Council of Greater New York.