Modular-building boosters, including traditional owners, developers, contractors and designers, maintain that off-site construction is faster, safer, leaner, greener, better quality and potentially less costly than site construction. But there is a big hitch, they caution: Building teams are not likely to reach modular delivery's pot of gold unless they plan and execute the off-site strategy properly. And that is no simple proposition.

"Everyone thinks it's a silver bullet," says Jeffrey M. Brown, the developer and general contractor for the Stack, a mostly factory-built seven-story residential building in Upper Manhattan that opened in May. "It really isn't unless you put the right ingredients in the bowl."

Few know that better than developer Forest City Ratner Cos. (FCRC) and its team building the world's future tallest modular tower: the 32-story B2 BKLYN residential building in Brooklyn, N.Y. Stalled at 10 stories, the B2 project at the $4.9-billion Pacific Park Brooklyn site, until recently called Atlantic Yards, is a glaring example of modular gone sour. The B2 project, designed by SHoP Architects, was going to take factory-built modular to the next level through the use of sophisticated digital tools to design, fabricate and manage assembly of the 930 modules.

Instead of a poster child for improved high-rise modular, B2 has become the poster child for modular run amok. Unable to solve their differences privately over delays and cost overruns, FCRC and Skanska USA Building Inc.—B2's construction manager and FCRC's partner in a new modular plant, called FC+Skanska Modular—are battling it out in court.

Despite the situation, both Skanska and FCRC say they are committed to factory-built modular. "We believe in modular as the future of the industry," says Richard A. Kennedy, Skanska's co-chief operating officer.

In a Sept. 4 letter to Kennedy, FCRC President and CEO MaryAnne Gilmartin says, "We remain resolute in modular technology's potential and promise."

Modular-building veterans are rattled by the B2 feud. "I'm angry because it gave this industry a black eye," says Tom O'Hara, vice president for business development at Capsys Corp. The factory builder is supplying modules for a 65-unit residential building in the Bronx, N.Y., called 3361 Third Avenue.

Modular is of interest to traditional builders because, in part, it has been identified as a means for improving building production. Collaborative delivery and advances in digital tools for design, coordination, clash detection, project management and fabrication support the movement, as do advances in lifting equipment.

"This is not a new process, but there is newfound interest of late," says Tom Hardiman, executive director of the Modular Building Institute (MBI).

Until 2009, the 31-year-old MBI had no traditional contractor members. Now, there are a dozen, including Gilbane Building Co., Mortenson Construction and PCL, but not Skanska or FCRC.