Prefabricated Tower May Rise at Brooklyn’s Atlantic Yards

A 34-story structure at Atlantic Yards would satisfy an obligation of the developer, Bruce C. Ratner, to build affordable housing.

By CHARLES V. BAGLI

In a bid to cut costs at his star-crossed Atlantic Yards project in Brooklyn, the developer Bruce C. Ratner is pursuing plans to erect the world’s tallest prefabricated steel structure, a 34-story tower that would fulfill his obligation to start building affordable housing at the site.

The prefabricated, or modular, method he would use, which is untested at that height, could cut construction costs in half by saving time and requiring substantially fewer and cheaper workers. And the large number of buildings planned for the $4.9 billion Atlantic Yards — 16 in all, not including the Nets arena now under construction — could also make it economical for the company to run its own modular factory, where walls, ceilings, floors, plumbing and even bathrooms and kitchens could be installed in prefabricated steel-frame boxes.

The 34-story building, with roughly 400 apartments, would comprise more than 900 modules that would be hauled to Atlantic Yards, lifted into place by crane and bolted together at the corner of Flatbush Avenue and Dean Street, next to the arena.

Mr. Ratner’s development company, Forest City Ratner, has been investigating modular construction for a year, but has kept its plans secret. MaryAnne Gilmartin, executive vice president of Forest City Ratner, confirmed Wednesday that the company was seriously considering the modular method, although, she added, no final decision had been made.

The company has also continued to design a conventional tower. Forest City hired Ove Arup & Partners, a prominent engineering firm, for the modular work, while SHoP Architects is working on designs for both types of buildings. The developer has also recently directed real estate brokers to scout for sites in Long Island City, Queens, that would be large enough to accommodate the modular factory.

“The company is interested in modular, high-rise construction in an urban setting,” Ms. Gilmartin said. “It’s driven by cost and efficiencies.”

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But it would also infuriate the construction workers who were Mr. Ratner’s most ardent supporters during years of stormy community meetings, where they drowned out neighborhood opponents with chants of, “Jobs, jobs, jobs.”

“This is something that could be of great consequence to the building trades,” said Gary La Barbera, president of the Building and Construction Trades Council of Greater New York, an umbrella group for the construction unions. “We have never been supportive of prefab buildings, for obvious reasons.” After several years of delays, Forest City is under considerable pressure because of the difficulty in obtaining financing for the building and the weak real estate market. Work on the arena began a year ago. The developer has delayed the start date for the 34-story building, the first of the 16 planned for Atlantic Yards, several times. He now says he hopes to begin by the end of the year.

Under an agreement with the state, Forest City must begin excavation by May 2013, or pay up to $5 million in penalties for every year it falls behind.

Affordable-housing advocates, who supported Atlantic Yards because at least 30 percent of the more than 6,000 apartments would be reserved for low-, moderate- and middle-income tenants, have been pressuring the company to start building. But Rafael E. Cestero, the city’s commissioner of housing preservation and development, who had already set aside $14 million to subsidize 150 units in the first building, declined Mr. Ratner’s recent request for an additional $10 million in subsidies.

In pursuit of cutting construction costs, Mr. Ratner and Ms. Gilmartin recently traveled to Europe to talk to builders involved with what is currently the world’s tallest modular building: a 25-story dormitory in Wolverhampton, England, that was built last year in less than 12 months.

Mr. Ratner has also become captivated by a YouTube video depicting the assembly of the 15-story Ark Hotel in China in a matter of days.

Modular buildings are not new to New York City. The School Construction Authority has used the technology to build classrooms. Capsys, a modular builder at the Brooklyn Navy Yard, has built steel-frame, prefabricated housing up to seven stories tall in Clinton Hill and East New York, Brooklyn, and on Long Island.

Whether taller modular buildings can be built to withstand intense wind shear and seismic forces, while retaining cost savings, is another question, because the higher a structure is built, the more bracing it would require.

“At a smaller scale, prefab buildings have proven to be more efficient, more sustainable and less expensive,” said Thomas Hanrahan, dean of Pratt Institute’s School of Architecture. “The taller the building, the logistical and structural issues become much more complex.”

Tony Sclafani, a spokesman for the Department of Buildings, said city rules did not prohibit Forest City Ratner from using modular construction on the building. “There’s nothing standing in the way of a prefab building as long as they follow our regulations,” he said.

If it is feasible, Mr. Hanrahan and Ms. Gilmartin of Forest City said that Atlantic Yards is an ideal site because it is large enough for cranes to maneuver. “Industrialized and modular construction is an idea whose time has come,” said the architect James Garrison, who worked briefly on the project.

Modular construction saves time because the building components can be put together at the same time the foundation is being dug, and because the factory is indoors, weather is not a problem. Materials can be bought in greater bulk and stored on-site. More of the work is done horizontally, on the factory floor, rather than vertically, saving the time it would normally take for all the plumbers, carpenters, electricians and others to move up and down the structure every day.

But it is the labor savings that are suddenly worrying some union officials, who were repeatedly asked by Forest City to mobilize their members for years of raucous community meetings.

The state and the city agreed to provide $300 million in direct subsidies for Atlantic Yards, in part, because Forest City insisted that the project would generate “upwards of 17,000 union construction jobs.”

Not to worry, Ms. Gilmartin said, “We’re a union shop, and we build union.”

But under current wage scales, union workers earn less in a factory than they do on-site. A carpenter earns $85 an hour in wages and benefits on-site, but only $35 an hour in a factory.

And while modular construction employs a large number of carpenters, iron workers, who earn as much as $93.88 an hour in pay and benefits, could lose a lot of jobs.

One construction professional, who was familiar with Forest City Ratner’s plans but requested anonymity because he did not want to anger the company, said, “The incentive is to move as much work as possible to the factory from the field.”