If Walls Could Talk

ACS Construction built more than 6,000 square feet of energy-efficient living with Nudura insulated concrete forms.

Building technology has come a long way. Heightened concern about environmental issues has given rise to advanced building materials and new ways to build—ways that are strong and durable, as well as cost- and energy-efficient.

One of the newest materials is Nudura Integrated Building Technology. Nudura’s most advanced, state-of-the-art building product is insulated concrete forms (ICF). ICF homes are constructed out of preassembled polystyrene forms, which are manufactured without producing chlorofluorocarbons (CFCs or HCFCs). The rebar reinforced foam blocks are stacked and then filled with concrete to build foundations and walls.

And though its name implies a technical complexity, Dale Grover, of ACS Construction, compares it to a child’s toy.

“They are like adult Lego blocks,” says Grover, who has been building ICF homes for four years. “They lock in place just like Legos. It’s the same exact idea.”

Grover became a believer of ICF when he started researching construction for his own Hawaii Kai home. He came across Nudura, took training classes and is now the state’s representative. The former pilot for Aloha Airlines devotes full time to building what he calls “energy efficient, quality homes that are going to last.”

Today, more and more builders and homeowners are discovering the benefits of building with ICF homes. The advantages of ICF are numerous, Grover says, but three stand out for Hawaii’s homeowners—hurricanes, energy efficiency and termites.

Hurricanes: Due to Nudura’s design, its walls have up to nine times more axial load resistance than a typical wood-frame house. This protects homes from strong winds and hurricanes.

One of the greatest dangers to homes during a hurricane is traveling debris. Researchers at Texas Tech University mimicked the conditions of a 15-pound 2” x 4” traveling at 100 mph. The results? The ICF walls stayed intact and obliterated the 2” x 4”s. There was damage to the exterior siding covering, but not to the concrete wall itself. According to the Portland Cement Association, ICF homes can withstand winds up to 200 miles per hour, which is a Category 3 hurricane.

“I did a trade show on Kauai, and many people already knew about ICF,” Grover says. “They know about hurricanes over there … this stuff will one day take over the industry. It’s already happening in different states on the Mainland.”

Energy Efficiency: According to the Consumer Energy Center, a nonprofit organization, manufacturers of ICF products predict that heating and cooling costs can be reduced as much as 75 percent. Heating—where there is a greater majority of savings—is not an issue here in Hawaii. But studies show that ICF walls, with no air spaces or studs, vastly reduce air infiltration. ICF homes take less energy to cool than comparable-sized wood-frame homes, and are up to four times more energy efficient. Much of the savings come from the effectiveness of polystyrene insulation. Polystyrene alone rates an R-22, compared to the R-9 of traditional homes. (R values are standard measurements of thermal resistance.) Plus, the ICF’s concrete core gives the structure thermal mass, which also helps keep houses cool.

Tilt and turn vinyl windows, by Canadian company Welo Windows, offer energy-efficient insulation with triple air chambers and triple-continuous weather stripping.

Termites: ICF homes are constructed with foam and concrete. No wood, no food. In addition, poured-in-place homes are sealed tight.

“They are really as tight as you can make a house,” Grover says. “It’s solid. Bugs can’t get in there. Plus, there is no wood in the house. Termites are not an issue.”

Other noteworthy perks include fire and sound protection, plus longevity. Because of their concrete cores, ICF homes are four times more fire resistant. Concrete does not burn like wood. It does not melt like steel. In one test, ICF walls were subjected to continuous gas flames up to 2,000ºF for up to four hours. None of the walls failed structurally.

Grover demonstrates another benefit to ICF—peace and quiet. He stomps hard on the second floor of the home. “See, no noise. This is concrete, the sound doesn’t echo on the floor below.” He opens a window, where the hum of cars on the Pali reverberates. He closes the window and the sound stops. “See, no noise.”

“This house will last 200 to 300 years, minimum,” Grover says. “Termites? Not an issue. Hurricanes? Not an issue.”

The cost of building an ICF home is about 10 percent more than a traditional home. The price of materials is higher, but labor costs and construction times are lower, because ICF homes go up fast. The three-story Nuuanu home took one year to complete.

Acknowledging that building materials impact the value of an investment for its lifetime, Grover says, “To me it’s a no-brainer. Owners and builders are going to want ICF homes as they become more prevalent. More and more, it’s coming around.”

The master bedroom’s windows open up to the Nuuanu stream that runs along the property’s backyard. The room’s wood flooring is a Peruvian Olive, a rich hardwood in the teak family.

Grover has built six homes on Oahu and is expanding to the Neighbor Islands. He says the homes sell themselves.