Every home builder in the country knows there is a shortage of skilled tradespeople that will only grow more acute. But very few have the vision, money and wherewithal to pursue a large-scale solution and implement it. One of them is William J. Pulte, founder and chairman of Pulte Homes Inc., the second-largest builder in America with revenue last year of $11.71 billion.

Seven years ago, Pulte started grappling with the labor issue. When he built his first house more than 50 years ago, he said in a recent interview, the primary source for skilled labor was the families that had been practicing the trades for generations. But in recent decades, families that once raised their children to be carpenters or masons began to encourage their offspring to become doctors and lawyers, and other young people were not being recruited in the numbers needed.

After some months of analysis, Pulte and the team he assembled concluded that the most promising long-term solution was to take computer-instructed machines that could be operated by less-skilled workers and adapt them to home building. The machines already existed for some aspects of home building; for the rest they were on their own.

Once Pulte made the leap to computer-driven solutions, he and his team began to rethink the building process from the foundation right up to the ridge vent at the peak of the roof. Machines could substitute for skilled framers, but what else could they do? For example, how could machines improve quality? What combination of machines and materials would make a house more energy-efficient? Would the houses look any different? The answer to that one, he knew, had to be no. Buyers in every market have consistently shown that they favor a very traditional look. The houses could be built differently, but they would have to look the same as those built the old way.

After five years of trial and error, designing and redesigning the machines and the process and building entire houses or parts of them in the Detroit area, where Pulte Homes is headquartered, the company was ready to go.

The firm built its first plant in Manassas, and started moving "product" out the door in December 2003.

After a recent factory tour followed by a visit to a nearby Pulte Homes building site, I concluded that William Pulte may have precipitated a sea change in the home-building business -- he has shown how computers enable a builder to construct a better house in less time. At the Manassas facility, his firm is producing tract-built, energy-efficient houses with the construction quality that is normally associated with custom-built homes.

Visitors to the plant will not see the exotic hardwood floors and tumbled marble that say "custom" to most home buyers; they will instead see the things that say "custom" to a home builder:

* Machinery that produces straight and true walls, which means that the framing pieces will fit together easily and the framing will go up faster.

* Extremely stiff floor systems that don't squeak and that eliminate those late-night phone calls from irate buyers complaining that every time they use their treadmill the whole house shakes.

* An energy-efficient building envelope that will produce an unusually comfortable house with rooms that are not drafty, an inside temperature that won't vary from room to room and floor to floor, and a house that costs far less to heat and cool.

Certainly one reason that the casual observer's take on Pulte Homes' Manassas operation differs from the home builder's is that the company is not focusing on turning out finished houses there. It fabricates only the parts related to the building envelope and the structural framework. Even taking this into account, a layperson can have a hard time connecting all the dots because the houses do not leave the plant in sections on a flatbed trailer -- the "wide loads" that you see moving slowly on the highway. They leave in wall sections that are assembled at the building site.

Pulte's desire for a better-built house led to some surprising choices. Not only does his company build all the relatively lightweight walls that are easily transported to a building site, it also builds the heavy concrete foundation walls that form the basement and are harder to move around. There were several reasons for this, said Chuck Chippero, head of Pulte Home Sciences, the division that designed and operates the plant.

The first was that to assemble the houses easily and quickly on site, all the walls, including the foundation, must be straight and true.

If the foundation walls are out of plumb, which they often are when they are poured in place at the building site, getting factory-built walls to fit on top of them is difficult and time-consuming, Chippero said. When a house is site-built piece by piece, it doesn't matter if the foundation walls are out of plumb because experienced carpenters can finagle the framing pieces to fit.

In making its own concrete, Pulte Homes can also control the mix and the strength, Chippero said, producing foundation walls that are two to three times stronger than conventional ones. They can support the unusually heavy loads of the biggest houses and can be moved to the site without damage. Because the added strength makes the walls much denser, moisture can't penetrate and the basement stays dry -- a big hit with homeowners, Chippero said.

Pulte's exterior walls are structural insulated panels. A rarity in the Washington area, SIPs are readily available in colder climates.

A SIPs panel is made by sandwiching polystyrene foam between extremely large sheets of oriented strand board. Compared with the conventional exterior walls made with wood studs that most builders use, SIPs walls are more energy-efficient and can be made much faster.

Giving an example, Chippero said that in about 10 minutes, 12 people working with computerized machines can make an 8-by-24-foot SIPs wall that combines structural framing with exterior sheathing and insulation; cut the holes for the windows and doors; attach house wrap (to prevent any rain that gets under the siding from getting into the walls); install the windows and door frames; and load the wall on a skid to be taken to the job site.

With conventional construction, the same job would require four separate trades: carpenters to frame the walls and add the sheathing, a crew to install the insulation, a crew to attach the house wrap and a crew to install the windows. For a 3,500-square-foot house, it would take five or six workers eight days to frame both the exterior and interior walls using panelized stud walls that were previously assembled in a factory. (If the crew started from scratch and "stick-framed" the house, it would take an additional day.) Three more days would be needed for each additional trade to do its work. At the Pulte Homes factory, they can build all the walls for the same size house in four hours, Chippero said.

In an industry in which success is eventually copied by a competitor, will other builders start fabricating parts of their houses in factories?

The cost will discourage many. Few builders could have afforded to bankroll the research and development and the initial work in the Detroit facility, and the cost of building a plant like the one in Manassas would be very high.

When asked exactly how much it all did cost, Pulte's chairman demurred. But with the resources available to him -- Pulte Homes' net income in 2004 was $987 million -- he could afford to spend a bundle, and judging by what I saw, you can bet that he did.

Katherine Salant can be contacted at www.katherinesalant.com.

(c) 2005, Katherine Salant

Distributed by Inman News Features

At the Pulte Homes plant in Manassas, finished foundation walls await loading onto a tandem trailer for delivery to a job site. The process allows houses to be built faster.Sixteen exterior wall panels, which were made in less than three hours, are protected from damage by specially designed racks until a crane can lift them into place.