Construction Cautions Despite these advantages, not all projects lend themselves to modular. For instance, you can’t do slab-on-grade construction–a modular building needs some type of crawl space. You can’t build more than five or six stories. And you need to be able to get the boxes to the site, along with a crane to lift them into place. An extremely narrow road, or trees that can’t be disturbed, might make this impossible.
Even where modular looks like good fit, builders who are new to modular must make sure they and the manufacturer understand each other’s needs and limitations. The Mid-Peninsula Housing Coalition, a Redwood City, Calif., housing nonprofit, recently completed a set of rental apartments for farm workers in Watsonville, Calif. According to Bill Bane, the Coalition’s director of construction, there were some communications problems between the manufacturers and the civil and structural engineering consultants. One resulting problem concerned water connections for fire sprinklers. The manufacturer said it understood the requirements, but then the connections ended up on the wrong side of the foundation.
“We’re still on the learning curve,” Bane says. “Our consultants need to learn to think like manufacturers, and the manufacturers need to learn our needs.”
While nearly all multifamily modular projects are custom-designed by the property owner’s architect, most designs must be tweaked to fit a manufacturer’s production and shipping process. Obviously, a manufacturer needs to tell the architect where and how electrical and plumbing will need to come together in the finished product.
But the most important variable is the size of the boxes themselves. For multifamily companies who want to go modular, it’s most cost-effective to order the maximum-size boxes that can be transported on roads. In most states, those dimensions are 14 feet wide and 64 feet long. This not only saves trucking charges (it’s cheaper to ship one large box than two smaller ones), but also makes better use of manufacturers’ production lines. “We’re charging labor and overhead for our production space in spite of the size of boxes we’re making,” says Boniello. “If your project requires 8-foot-by-34-foot boxes, you’ve wasted a lot of that production space, and you lose efficiencies.”
Each box style also has to get approval from code authorities, something you need consider if you deviate too far from standard modular box sizes. “Once you start moving walls, you may have to go through the state approval process,” says Emmett Hagood Jr. of EBH Inc. Architecture and Urban Design, the architect on the Brainard Street project. That, of course, can add unwanted time to the build.
Finally, all decisions are final. Because boxes are shipped to the site totally finished on the inside, everything needs to be planned down to the last detail. “We need answers to all questions before we start construction,” says American Homes’ Jack Julo. “There are no change orders.”
In the future, there may not be so many questions to answer. Some manufacturers, including All American, are starting to bid projects turnkey. “Give us a building pad and we’ll take it from there,” says Julo. “That’s where things are going in the future. We will no longer be just a manufacturer; we’ll be a construction company.”
–Charles Wardell (clwardell@earthlink.net) is a freelance writer in Vineyard Haven, Mass.