More new homes built with concrete form insulation

FORT WORTH, Texas — Here's a concrete solution for shocking energy bills: a foam home.

There's no cooler option, according to Matt McCoy, a Wimberley, Texas, resident who lives in one.

"I live in a 3,500-square-foot house," he said. "I pay the same for electricity that I paid two years ago in a 1,400 square-foot house."

McCoy is chilling, courtesy of insulating concrete-form construction, or ICF as it's known in the building trades. Instead of the typical stick-and-brick construction used in his previous house, his new home's walls are a 6-inch layer of steel-reinforced poured concrete, between two thick layers of high-insulation polystyrene foam.

It's like a conventional poured-concrete wall, except that the foam forms stay in place to provide insulation. Once the concrete is cured, the foam also becomes the backing for exterior and interior finishes, such as brick and drywall. The forms combine a vapor barrier, nailing surface and insulator in a single unit. And ICF buildings can come in virtually any architectural style, exterior and interior.

As of 2005, the technology accounted for 5.7 percent of residential construction nationwide, up from only 0.2 percent in 1995, according to the Insulating Concrete Form Association of Glenville, Ill. Residential ICF construction has risen 73 percent in the last five years; commercial applications are up a whopping 172 percent, according to Vera Novak, the association's technical-services manager.

"Our business has doubled every year in the last six years," said McCoy, president of South River Construction in Wimberley. "We come out with these giant Styrofoam forms. It's like Legos. You just stack 'em up and pour concrete in 'em."

Tom Misfeldt and his wife were spending $500 to $700 per month on utilities to heat and cool their 4,000-square-foot house in Fort Worth's historic Ryan Place neighborhood south of downtown. Then they built a 2,900-square-foot, ICF structure south of Fort Worth.

The Misfeldts' most recent utility bill was a little more than $300, and that's counting the electricity they use to pump water out of their well, which provides for lawn watering and household use.

Temperature fluctuation

Larry Smith has almost finished an ICF home in the Double Y neighborhood in Arlington, Texas. Without heating or air conditioning, temperatures should only fluctuate 4 degrees per 24 hours, he said.

"It's like a cave," Smith said.

Most of Smith's interior walls are conventional wood framing, but there's no wood in the roof. It's a flat, 4,000-square-foot ICF party deck. He figures that a roof that's impervious to hail and high winds will net him a nice homeowner's policy saving.

Bernie Henyon, a Fort Worth Allstate insurance agent, said owners of ICF houses save from 10 percent to more than 50 percent in premiums in some cases.

ICF also reduces noise and offers fire and wind resistance. Experts estimate that ICF buildings are up to 8.5 times stronger than wood-framed buildings.

Texas Tech University's Debris Impact Testing Facility has confirmed ICF's resistance to tornado-level winds: In tests, 15-pound, two-by-four studs were fired from a pneumatic cannon at ICF walls at speeds of 100 mph. The concrete was unscathed. Steve Kissell, project manager for Fort Worth-based G.L. Barron Co., said his firm plans to use the ICF technology in designs in two schools, including one in Fort Worth.

Construction costs are a bit more, Kissell said. But on the Fort Worth project, his firm was able to decrease the air-conditioning unit from 38 to 27 tons, which reduces the cost.

Research findings

Research by the Insulating Concrete Form Association shows that houses built with ICF exterior walls need an estimated 44 percent less energy to heat and 32 percent less energy to cool than comparable wood-frame houses.

"I'm going to be putting a lot of money in the bank," said Smith, who calculates that he'll recoup the 5 percent extra it cost to use ICF in three years.