In between, an intricate ballet of carpenters and electricians, plumbers and painters work above, below, and inside each apartment amid the thud of nail guns and the smell of fresh paint. Step by step, the apartments take shape until they’re basically livable, minus utilities. Then they are sent on their way, many of them bound for Boston, where they’re stacked like shipping containers to create apartment buildings.

SAINT-BENOIT-LABRE, Quebec — At one end of a football-field-size plant 40 miles north of the Maine border, workers lay out boards and cover them with plywood to make a floor. At the other end, an 800-square-foot apartment — bathroom fixtures and all — is swaddled in protective wrapping and rolled out to the parking lot.


The factory — operated by RCM Group — makes about 600 apartments and hotel rooms a year, many of which have been sent recently to Allston, Somerville, and Charlestown, with more coming to Quincy, Newton, and Beverly.

Faster and, some say, more efficient than traditional wood-frame construction, modular building is growing more popular among developers in housing-starved Greater Boston.

While worries about quality and occasional pushback from construction unions have long helped keep the building method from being widely adopted here, those concerns are easing. The relentless pressure of increasing costs has more builders warming up to the idea of factory-built apartments, saying they could be a key factor in addressing the Boston area’s housing crunch.

“Modular’s time has finally arrived,” said architect Arthur Klipfel, president of Oaktree Development, which is planning a modular building on Austin Street in Newton. “There are enough projects that the idea can get some traction.”

It’s definitely getting attention. Major investors have pumped more than $1 billion into Katerra, a Silicon Valley startup with a factory in Phoenix and plans to expand into the Northeast. A local startup, with strong ties to developers WinnCompanies and Suffolk Construction, is exploring off-site construction as a way to boost affordable housing in Boston. And developers hoping to make the most of the region’s housing market while it’s still hot are looking for any advantage they can find, even if that takes them to a factory in Quebec.


Construction experts, however, are quick to point out that modular building is not much cheaper than traditional on-site methods. Materials cost the same, or perhaps more when you count the double walls and floors that come from stacking units alongside each other. Labor in a rural factory may be less expensive than union workers in Boston, but those savings are eaten up by the added costs of trucking full-size apartments six hours through the Maine woods to the Boston area and renting the massive cranes needed to lift them into place.

It is, though, a faster way to build homes. RCM

— a leading supplier of so-called modular, multifamily housing in New England and Eastern Canada — can pump out 14 apartments a week and stack that many on-site in two days. Even with extra design work beforehand, and connecting utilities once the units are in place, building modular can shave a few months off a project that would typically take two years.

“When you’re saving time, you’re saving money,” said Jonathan Miller, vice president of development at LBC Boston, which is building a 171-unit modular project in Quincy Center. “That’s really where you end up benefiting.”


It also means a lot of front-end work on design and architecture, to make sure everything fits together. Once the units are built and trucked to the project site, there’s no going back, even if, say, a vent connection is in the wrong place.

“You’ve got to sweat the details,” said John Tocci, the chief executive of Tocci Construction, which is building the Graphic, a 125-unit modular building in Charlestown. “If you make the wrong decision, you’ve made the wrong decision 300 times.”

A lot of that planning goes on at RCM, where Gilbert Trudeau employs about 50 designers, engineers, and project managers, along with his 125 construction workers. Every unit on the assembly line has a book of detailed construction plans attached, and each one is built exactly the same way. That standardization, he argued, improves quality; just as a surgeon gets better by doing the same operation over and over, his crews get better by doing the same job every day, in a climate-controlled environment, with their tools close at hand.

“For a lot of people, construction is hanging off the roof banging a hammer,” Trudeau said. “In here, I’m trying to eliminate that.”

A living room with a fireplace inside a modular home, used in some cases for apartments, is prepared for shipping. Francis Vachon for The Boston Globe

There are some who would like to bring this style of construction to Massachusetts in a bigger way. Talk of a plant here has percolated in construction circles for years, with various developers and builders studying sites and costs. Some of those talks have involved construction unions, such as the New England Regional Council of Carpenters, which considers a local plant a way to train incoming workers, while producing housing on a mass scale.


“You can’t create the tens of thousands of units we need, at a price point that makes sense, without this,” said union executive secretary treasurer Tom Flynn. “Especially low-rise multifamily buildings — that’s where the greatest need is.”

The challenge is volume. Flynn estimates a Massachusetts modular plant would need to pump out about 2,000 units annually for it to make financial sense. In busy years like the last few, that would not be a problem, he said. But in a slowdown, keeping the doors open would be hard.

“If you can’t guarantee around 2,000 units a year, the economics just don’t work,” he said.

During the lean years of the recession, Trudeau said, RCM kept busy building mining-camp dorms until the housing business came back, and they’ve branched out to do hotels, college dorms, and assisted-living facilities.

These days, though, the Canadian plant — in business for 18 years — is booked solid well into 2019, with a lot of apartments scheduled to roll off the assembly line and get placed on a truck. Many of them will be headed to Boston.

Wrapped and ready to be shipped, completed modular homes wait at the RCM Group yard. Francis Vachon for The Boston Globe

Tim Logan can be reached at tim.logan@globe.com. Follow him on Twitter @bytimlogan.