While no ICF homes built by Denny Yeackley of D & M Building Systems have been hit by tornadoes, he knows of other ICF homes that were and they were essentially unaffected. Jim Hymbaugh of Hymbaugh Construction also works in a tornado zone. He cites a June 2004 tornado that destroyed an entire neighborhood in Kansas City, Kan., except for one small ICF house. Although there was a little damage to the vinyl siding, a few missing shingles, and broken windows from flying debris, the residents could have moved back in as soon as the power was turned on. "If the walls don't fail, the roof doesn't usually leave," he points out.

Energy efficiency

In these days of ever-increasing energy costs, the efficiency provided by ICFs is attractive. According to industry figures, occupants can save up to 70 percent of their energy bills for cooling, heating and dehumidification because of air infiltration control and insulated thermal mass.

But there is consumer resistance to building with ICFs because the initial cost can be up to 10 percent higher than other materials. The payback period for this extra investment is from two to five years, depending on energy prices. Yeackley, who builds with both The Standard Wall and Reward Wall Systems ICFs, says many consumers are sticking with the familiarity of wood frame homes with their traditional insulation, even as they embrace energy-efficient windows.

"People have trouble with that higher upfront cost," Hymbaugh says. "Anything you do that saves energy is going to save you money. Some lenders are recognizing those energy savings and will loan a little more money toward the house. Because the heating and cooling costs are lower, people can afford a bigger monthly payment."

In his area, where temperatures drop below zero during the winter, energy costs increased over a third last year and most heating bills doubled. His customers have reported spending only $500 for a winter's worth of heat compared to $350 per month for conventional homes.

"The houses most people are building today, they won't be able to afford to live in 20 years from now because they'll be too costly to heat," he notes. "It's hard to convince people to build a house that's as energy efficient as possible."

Hymbaugh also builds new and replacement home basements using ICFs. Having an ICF basement in a regular home provides some energy savings, as the building code requires R-10 insulation for basements and ICFs come with R-22+ built in.

Other benefits for consumers

People with allergies and asthma will enjoy living in ICF homes because they are free of volatile organic compounds from chipboard and release oil. "These homes are relatively airtight, so there are no outdoor pollens and pollutants entering the home," Buttrey says. "Because of the insulated thermal mass, there's no dewpoint transfer to create condensation and therefore no risk of mold."

ICF homes are also much quieter than other types of homes, so occupants won't hear sirens, traffic and outdoor sounds. While the standard American home has a 10- to 30-minute fire rating, ICF homes are rated at up to four hours depending on wall thickness.

Other benefits for contractors

Cold weather can make building difficult or impossible in winter for northern contractors, but that's not a problem with ICFs.

"We can pour concrete down to 15 degrees below zero and it won't hurt it, so we can work all through the winter," Yeackley says. "Concrete creates its own heat when it starts setting up, so it won't freeze inside the ICF forms."

Hymbaugh describes working with ICFs as much easier than doing structural concrete using hard forms, which his company did until four years ago. Because ICFs are not removed, there is no need to cover them with release oil. His workers have fewer injuries because the ICFs are so much lighter than the old forms.

"The work is much less stressful and cleaner than with regular forms," he says.

There is no need to store the forms or move them between jobs since they are not reused. The upfront investment for forms is also much lower, with ICFs costing about $7,000 to $10,000 per home compared to $150,000 for traditional, reusable forms, Hymbaugh says.

More education needed

About 60,000 ICF homes are built in the United States annually today and the number increases each year, but there is still significant resistance from some in the industry.

"The biggest problem we have is with building officials and architects," Hymbaugh says. "They don't want to do something different than they did last week. What we've seen is that it's consumer driven. The homeowners are demanding that their homes be built out of concrete."