Factory-made homes continue to gain architectural credibility with styles that span the design spectrum. While they may be cost-effective, many are far from cheap.
By now it's fair to say most people don't confuse prefab houses with mobile homes. Prefab is simply a different system for building a regular house, of almost any style, producing it in either modules or panels in a factory.
With modules, there's a lot of extra engineering involved: After all, at the factory and at the homesite, pieces of the structure have to be picked up by a crane and set in place, first on the delivery rig and then on a concrete foundation -- and in between they bounce around for miles on a truck.
With panels, sections of walls, complete with innards such as electrical wires, are stacked on trucks, then linked together on-site. When finished, prefabs look like regular houses.
People do, however, continue to equate prefab with cheap, or at least considerably cheaper than traditional "stick-built" construction. But there is a wide spectrum of prefab houses and the companies that make them.
At one end, you have factories that spit out econoboxes that, despite their superior engineering, can resemble shipping containers. They include the one-bedroom, one-bath "i-house" by Tennessee-based Clayton Homes, which can be had for a base price of $75,812. Adding upgraded flooring and appliances takes it to about $85,000 including delivery, or about $117 a square foot. ECO-Cottages by Nationwide Homes of Martinsville, Va., offers a 513-square-foot, one-bedroom, one-bath "Osprey" cottage starting at $59,500, or $116 a square foot. (Prefab prices do not include the cost of the land, foundation or site-prep work.)
At the other end of the cost spectrum are such firms as California-based LivingHomes, which offers high-style contemporary designs at square-foot costs that range from $220 to $250, and much more for custom designs. That doesn't even include design fees. What you're getting, the company says, is a soaring architect-designed house -- steel frame, lots of glass -- for 20 to 40 percent less than a similar house would cost if it were site-built.
Compare these numbers with a 2,200-square-foot house currently offered by Ryan Homes in Clinton, Md. -- $121 a square foot including the land it sits on -- and the decision to go prefab is not as clear-cut as it may seem.
Chris Brown and his wife, Sarah Johnson, own a prefab cabin called Lost River Modern. During construction, Brown kept a blog, including his estimates of what he thought things were going to cost and then the real dollar amount -- a staggering $356,000 total to build a nice two-story, three-bedroom, two-bathroom 2,048-square-foot house in far-out West Virginia.
The cabin is part of a mini-slice of the prefab world: stylish, higher-end houses designed by architects interested in homes that are built in a way that's more labor- and energy-efficient and less wasteful than site-built houses.
"Prefab is just a tool -- it's a process rather than a design," said Geoffrey Warner, principal with Alchemy Architects in St. Paul, who has won acclaim for his prefab weeHouses.
Prefab's efficiency means "you can save 20 percent fairly easily" as opposed to a comparable site-built home, he said.
But many of today's prefab buyers are using that savings to add other features to their homes. "Prefab is definitely moving upscale," Warner said. A big factor is today's tough lending environment, which makes it hard for buyers on tight budgets to even get financing. "Our clients are those able to get loans."
Prefab awareness and cachet also have increased. "It's taught in universities a lot more, and you can hardly find a young architect who doesn't have some prefab" (in his or her portfolio), Warner said.
His firm recently won a 2011 Minnesota AIA (American Institute of Architects) Honor Award for a prefab weeHouse retreat in Marfa, Texas, evidence of prefab's growing architectural credibility. "It's seen by our peers as a nice project, not just a [building] method," he said.
Brown and Johnson wanted a getaway house that they could rent out, and then they saw the winner of the 2003 Dwell Magazine prefab-house competition. Sixteen architects and designers were invited to create an innovative prefabricated house for $200,000 -- one more effort to stoke the fire under prefab, which is always threatening to peter out in the face of market realities.
The winner was Resolution: 4 Architecture of New York. Res4 had a relationship with a builder, Simplex Industries of Scranton, Pa., which was helpful because designing a prefab house is only the beginning; you also need access to a factory that can construct it. Architects don't own factories, as a rule, and mass-production factories are not necessarily disposed to interrupting their assembly line for a small project.
With contemporary design there's an additional challenge: The architect or the owner has to find a modular construction company that is attentive to finishes. "With modern," Brown says, "you can't hide everything with molding like in traditional-style modular houses."
An advantage of prefab is supposed to be the time savings, and it's true that the factory can start on the component parts of the house while a crew is still pouring the foundation -- impossible, of course, with site-built construction. But tweaking machinery and refining designs still takes time. Brown estimates the house was "in the factory" for a year.
Another year was spent after delivery, finishing details such as some complicated flashing for the Charles Goodman-style "butterfly" roof and the interior, with Brown and his brother-in-law providing a lot of the labor. (They also applied the exterior cedar siding and built the deck, then tackled the interior of the lower level, even building the staircase and tiling the bathroom.)
Brown, a graduate student in English literature, said the "real advantage" was that he and Johnson, a nurse, "didn't have to manage a building site" that was almost three hours from their home in suburban Washington.
Without the land cost, excavation or the $12,000 for the road up the side of their hill, Brown and Johnson calculate their square-foot cost as $150 to $160, "the low end of prefab," Brown said. At least of "architect prefab."
Staff writer Kim Palmer contributed to this report.