The beauty of panelized houses is that they can be framed–and weatherproof–in about 10 days, according to Bethesda Bungalows project manager Brad Beeson.
“Everything is exposed to the elements a lot less, which means less of a concern about mold,” he points out. “Also, we don’t have to have big stacks of lumber lying around for weeks on end, which is extremely helpful as we’re working in small infill lots.”
That’s why the KellyGreen home, like most of Bethesda Bungalows’ infill projects, is being built with pre-engineered wall sections and floor and roof trusses produced in a Pennsylvania factory.
Employees at Greencastle, Pa.-based Foremost Industries electronically engineered the KellyGreen floor plans from the architect’s renderings. After CAD drawings were complete, the pieces took only a few days to produce, says Foremost sales representative Tom Carr. “We’re building a complete system,” he notes.
The most challenging part of the process was trucking the pieces–some as large as 24 feet wide–75 miles on a flatbed trailer and squeezing them into the extremely tight Bethesda, Md., site. On arrival, a crane placed them on the foundation and a framing crew experienced in panelized construction carefully assembled them.
“We bring loads to the site as needed because the conditions there don’t allow for any storage,” Carr points out. “We show up at 9 a.m., when most of the neighbors are at work, and when they come back the pieces are already in place.”
PROS AND CONS
PANELIZATION TIPS
Pre-construction:
–Decide early on if panelization is right for your project because it requires a good amount of up-front planning.
–Ask your architect for a design that can be easily replicated at a panelized factory.
–When selecting a panel manufacturer, consider the distance from the factory to the jobsite in order to save on shipping costs and to make factory visits easier.
–If advanced techniques such as 24-inch on-center framing or double-stud walls are crucial to your project, make sure the production line can handle those specs.
During construction:
–For infill homes, devise a parking plan for delivery vehicles and let the neighbors know when deliveries will take place.
–Use a framing crew that specializes in panelized construction.
The precise nature of high-tech panelization greatly cuts down on construction waste, Carr says. “We use everything down to a foot or less and anything that is not usable because it’s too small goes into a shredder.” The resulting sawdust is given to neighboring farmers for animal bedding.
Panelized homes are engineered for strength, Carr adds, plus, labor costs are reduced because panelized homes go up faster than stick-built structures.
Nevertheless, a factory-built shell has some limitations, Beeson says, including less flexibility for the designer or architect. “With panels, the finished product is not always exactly like it’s drawn, unfortunately,” he says.
For example, Bethesda Bungalows had to forego advanced framing options such as 24-inch on-center walls for the KellyGreen project because the Foremost factory is not set up for this type of spec. The builder also sacrificed double-stud corners, a technique that can earn LEED points. “That’s another drawback,” Beeson adds.
But overall, Beeson is very pleased. “It’s pretty darn good.”
Jennifer Goodman is Senior Editor Online for EcoHome.
