If "flat" is the new "up" in terms of performance in today's housing market, then "down" is the new "flat."
The Gig Harbor, Wash.-based Structural Insulated Panel Association (SIPA) said last month that the panel industry has “avoided the full force of the economic recession” and has maintained market share, despite the widespread carnage in the overall home building and construction market.
“Results indicate that the [structural insulated panel] industry experienced a 12% decrease in residential production volume in 2009, compared to a 28% drop in U.S. single-family housing starts over the same time period,” the association says.
So what accounts for this relatively steady position? SIPA believes its all about the green—green building, that is—and America’s recent preoccupation with energy efficiency.
"The rising cost of energy and concern over global climate change has really pushed green building into the mainstream," says executive director Bill Wachtler. "SIPs give architects and builders an easy way to create an air-tight building envelope that will improve the energy efficiency and durability of any home or light commercial building."
SIPs, a structural building system made from foam insulation sandwiched between two sheets of oriented strand board, plywood, or fiber cement panels, has long had a reputation as a technology with advantages over conventional stick framing. It’s resource-efficient, strong, and fast. SIPs is also reported to create a thermal barrier so tight that it can save homeowners up to 50% on heating and cooling costs.
It’s possible that there’s a renewed interest in the technology due to these benefits, but it cannot be overlooked that the panel industry’s share of the market also may be tied to the reduced overall size of new-home construction. Housing starts have come way down, while the technology’s market share is slightly down, so its size relative to the new-home market has held steady.
“2009 is the fifth consecutive year the industry has gained share in the residential market,” the group says. “It is now estimated that the panelized building system accounts for between 1% and 2% of U.S. single-family home starts.”
If 2% sounds like a paltry sum, it’s because it is. Its five years of “growth” notwithstanding, SIPs is still a bit player in the home building industry, and many wonder why.
Some argue SIPs homes cannot be made aesthetically attractive, but as SIPs gain fans, architects and designers are producing appealing houses with the technology--and in most cases, nobody but the builder will know the difference. (Still skeptical? Watch the slide show and see for yourself.)
That SIPs is a superior construction technology is also no longer in dispute—at least not among the builders and architects who have tried it and are convinced.
Builder Don Ferrier, of Ferrier Companies in Fort Worth, Texas, built his first SIPs house in 1985, and he loved it so much that today he builds 95% of his homes with it. “I would say that one-third of my customers come for a SIPs house, and the other two-thirds come for my experience building zero-energy or near-zero energy houses.”
Architect Toby Long, AIA, is a believer in site-specific solutions to construction problems, so he’s open to a myriad of building methods—prefab, modular, stick framing—but he too has a weakness for SIPs. “As a high-level response, SIPs is a pretty cool building technology from a construction and resource conservation perspective and from a long-term energy-conservation perspective,” says Long, principal of Toby Long Design and the owner of Clever Homes in San Francisco. “We don’t maintain long-term data collection with past clients, but anecdotally, they tell us that they have been amazingly satisfied with the performance of the panels.”
The coolest (no pun intended) thing about SIPs, Long insists, is that the building envelope is so tight and the R value so high “that the house stays at a more constant temperature.” As a result, inhabitants are more comfortable, air conditioners run less, and homeowners save money on utility costs.
Camille Urban Jobe, AIA, was introduced to SIPs through, of all things, a contractor. “My first SIPs house was in 2004,” says the principal of Urban Jobe Architecture in Austin, Texas. “I wasn’t so familiar with it, but the contractor had used it and liked it a lot.” Today, it’s a technology she tries to use when she has the opportunity.
SIPs technology also has been endorsed by the people whose job it is to assess the merits of a technology and its relevance to the home building industry. Oak Ridge National Laboratories in Oak Ridge, Tenn., for example, confirmed years ago that SIPs have a higher whole-wall insulation value and R-value than a conventional framed stud wall.
ToolBase Services, the technical information arm of the NAHB Research Center in Upper Marlboro, Md., says the technology’s “ease and speed of assembly makes it possible for houses to be placed under roof within days rather than weeks. While basic carpentry skills are required, assemblers need not have the skill levels of conventional framing crews, which can further reduce costs to builders.”
But while there is near-universal agreement on the performance of the product, the story gets murky and complicated when costs and application to home building are discussed. The industry claims that a SIPs house is cheaper to build because the tighter shell means the builder can specify a smaller HVAC system and save time on construction. Others are not quite sure this is exactly the case.
Long and Jobe say, for example, that some really good crews can frame a house really fast and for very little money. Whether or not building with SIPs is cheaper depends on the situation, though he’s not sure there is a price benefit, at least not for production builders. “There is a predictability that comes with SIPs,” Long says. “Builders can also accelerate the construction of a house.” He continues: “The big benefit is a better house, which is a good selling point for builders who have taken a long view of their work.”
Ferrier says a price comparison depends on what you’re building, where, and who is building it. You will never be able to build a SIPs house cheaper than a stick frame building that uses fiberglass batt insulation, he says, but if you’re building a stick-frame house that performs as well as a SIPs house, then the price is likely to be more equal.
“We’ve compared similar homes we’ve built with SIPs and with advanced framing techniques with single plate, insulated header, and foam insulation,” Ferrier explains. “The framed house was $9,000 less, but we still had thermal bridging in the studs. If we wanted to get to a similar SIPs product, we would have had to wrap the house in rigid foam board. At that point, the price would have been the same.” Plus, Ferrier believes the foam-insulated house is not as tight as the SIPs house.
If you ask the students at Tulane City Center, home of the applied urban research program at Tulane University School of Architecture, they’ll tell you that SIPs technology is great, but hard to build cheaper than conventional framing—especially in affordable housing. For years now, the URBANbuild, a design/build studio in which student teams design and build a prototypical home for a neighborhood in New Orleans, has been experimenting SIPs technology.
“We built house  with SIPs because we are trying to help a local nonprofit do research into the cost of building with different structural systems" in terms of upfront cost vs. life cycle costs, says Emilie Taylor, the former project manager for houses 01 to 04 and now manager of the Tulane City Center’s design/build projects. “So far we have built a traditional stick-framed house, a house with advanced framing techniques (still stick-framed), metal stud panel fabrication, and SIP panels. The upfront costs are substantially more for the SIP houses when trying to build an affordable 1,200-square-foot home for low-income families. But we are hoping they can make up some of that cost in energy efficiency.”
Getting more builders to use SIPs is a challenge because of the nebulous pricing issue, but it’s also possible that builders are intimidated by the technology. Though using SIPs is fast and resource-efficient, there is a learning curve. “It’s analogous to a regular framing job, but it’s also not something that is easily done the first time,” Long explains. “It requires three jobs to get your feet wet, but not until the third house do you really understand the system.”
Ferrier agrees with the three-SIP minimum for understanding, but even then there are things to consider, such as finding the right bid, the foundation work, and problem solving, among others. “Finding the right supplier is key,” he advises. Plus, it's not easy to make design changes on the jobsite once the panels arrive.
From Jobe’s point of view, builders will balk partly because the labor for framing is cheap, but she says builders will have a hard time convincing buyers to pay a higher price initially for a more energy-efficient house. “People are still stuck on what they see in TV and magazines,” she believes. “If they can save some money on the mechanical or on energy efficiency and get square footage for the large living room they want, they will take square footage nine times out of 10. Most of the time, they will sacrifice everything for square footage.”
Whatever the situation now, the architects and builders interviewed for this story believe the time is coming when energy efficiency will be the most important issue for buyers and argument for high-performance construction, including SIPs, will not be a hard sell.
For some buyers, builders, and architects, that's already happening. “It has been my experience that the inspiration for using SIPs does not come from the contractors," Long says. "It usually comes from the homeowners.”
Nigel F. Maynard is senior editor for products at BUILDER magazine.