Pulte Ramps Up Factory Component Building System
Looking to improve the quality of its housing and increase the satisfaction of its customers, Pulte Homes has moved beyond testing the waters for factory-built components and expects to deliver 500 of its system-built homes to the Virginia marketplace this year, Jim Petersen, director of research and development for Pulte Home Sciences, said in a May 25 presentation at the National Building Museum in Washington, D.C.
Pulte has been gradually gearing up for its new, more efficient alternative to stick-built construction since the late 1990s, Petersen said, and is ramping up production from a state-of-the-art, 109,000-square-foot facility in Manassas, Va. that is using 150 employees for its plant and field operations.
Able to push out 2,000 homes annually at an average size of 2,500 square feet, the plant is not yet operating at full capacity, Petersen said, and the 4,200-square-foot homes it is now producing are larger than had been anticipated.
As the factory’s production expands, the innovative process will account for an increasing share of the output of Pulte’s division in Virginia, which is now running at about 1,200-1,300 homes annually.
“We needed a market with at least 1,000 homes to justify the expense of the plant,” he said, and he calculated that the facility has a shipping radius of 100 miles.
The component homes and stick-built product are being built in separate communities.
Pulte buys and develops its own land and provides the house plans. As to the factory homes, “we haven’t built the same house twice yet,” Petersen said. Pulte uses its own software, which enables the company to “design every home as a job-specific solution.” This 3-D software has the capability of passing the loads through any design, providing the ability to customize all plans before any 2x4s are even cut. It is this kind of technology that makes each home both quick to produce and unique.
Pulte has its factory components down to a science:
- Foundations are made of high-strength, pre-cast concrete panels with extremely low permeability. Temperatures for sand, aggregate and water are controlled and production of the walls is not affected by adverse weather conditions, Petersen said. In stick-built homes, it is often necessary to add water in the field to keep the concrete flow even, which can compromise its strength. Joints are sealed with high-grade urethane adhesive and a water-proof coating is applied. Insulation is added to the outside of the panels and shotcrete is applied to any part of the foundation showing above grade. The foundation for a 2,000-square-foot home can be assembled in approximately five hours.
- Lightweight floor decks are made of open metal web trusses pressed onto OSB. Most wiring and plumbing can be installed within the trusses. The floors are stiffer than conventional floors and don’t vibrate.
- Pulte also produces its own Structural Insulated Panel (SIPs). The factory is capable of producing 24 feet of exterior walls every 10 minutes. The SIPs assure straight walls inside and out, greater strength than provided by 2x6 frame walls and a tighter building envelope.
- The interior walls are steel-framed and also manufactured in the plant. “Steel-framed interior walls will not rot, warp, split, crack or creep,” said Petersen. The walls run straight and true, reduce nail pops dramatically and they are non-combustible and 100% recyclable. They also dramatically reduce heating and cooling costs.
- Pulte’s Pultrim is a new exterior fiberglass trim that replaces wood, aluminum and vinyl. It provides a premium look and requires low maintenance.
- Pulte does not manufacture roof trusses in the factory. That is one of the components it will continue to purchase.
Pulte’s factory components enable the structure to be completed in the field in three to five days, cutting 20-25 days off the typical schedule for construction of a stick-built home. “The home is less exposed to the weather and it doesn’t become saturated,” he said, so that “the material doesn’t expand and contract as much as in a conventionally built home.”
In response to an ongoing decline in the availability of good trade workers, the components have been designed so that they can be assembled in the field by workers with a lower set of skills than those needed to build homes the old-fashioned way, he said.
Petersen boasted that Pulte’s system results in very clean building sites, consistently high quality that reduces service and warranty costs, basements that don’t leak, greater comfort, higher indoor air quality and less potential for mold.
For information on resources on systems-built housing available from NAHB, e-mail Eric Fulton, or call him at 800-368-5242 x8577.