In light of the recent energy crunch in some areas of the country, many home buyers are considering insulated concrete-form houses.

The homes -- built with blocks filled with concrete -- are significantly more energy efficient than traditional homes framed with wood, said Keith Perrine, general manager of Livingston Concrete in Sacramento.

Perrine said his company recently built a 3,500-square-foot insulated concrete-form home in El Dorado Hills, Calif., across the street from a traditional home of equal size.

"The gentleman in the ICF home is currently paying about $85 a month in utility costs, while the homeowner across the street in the wood-frame home is currently paying about $400 a month," Perrine said.

About 3 percent of the homes being built nationwide are using ICF construction, Perrine said.

ICF homes are 3 percent to 5 percent more expensive, builders said. However, Hugh Fowler of the Sacramento Municipal Utility District said the homes will save owners money in the long run.

"So the payoff is probably within a couple of years," Fowler said. "Yes, the houses are more expensive because they are more efficient, but the payoff -- in terms of monthly energy savings and comfort -- is more than worth the added price of the house."

Aside from lower energy bills, ICF homes are attractive to consumers because they allow for less noise and they've proven tough enough to withstand hurricane and tornado winds, said Dick Whitaker, president of the Insulating Concrete Form Association.

Also, ICF construction requires fewer man hours and allow for design flexibility, Whitaker said.