ATLANTA -- Phil Hennessy's Cobb County home is getting bigger. Much bigger.

The addition may look like a concrete fortress but it is not. The new construction is made of stryrofoam.

The home's 10-foot sections are known in the building trade as an insulated concrete form. Users stack them, connect them with glue and then fill them with concrete and rebar steel. A wall results from the structure. Builders can then easily create a window.

Rastra

Supporters say the material is a cost-effective, energy efficient alternative to other homebuilding materials, such as wood and concrete.

David West, a spokesman for Rastra, which distributes insulated concrete form. said the new material is good for homeowners and the environment.

"This is made out of insulated polystyrene, (which) you'll find in computer packing, coffee cups and furniture packing," he said. This is all recycled (and) basically diverted from the landfill."

The foam is mixed with concrete, which gives it strength and naturally repels termites.

Said West: "Nothing messes with it because of the lime that's in concrete."

The materials natural tendencies make it fire retardant, bug-proof and it has natural insulating properties.

Hennessy said the material has too many advantages to be dismissed, citing utility bill savings, structural integrity and noise abatement.

Insulated concrete forms are not new. The approach has been used for years in Europe and in the Southwest U.S.

"There's no reason to build with wood if you have a product like this," West said. "It solves all the problems that wood creates at a cost competitive price."

Said Hennessy: "I live the results so far."

He said the cost of the building material has been more than traditional stick built construction. Rastra officials, however, said their product is cost competitive with other building materials and less than the cost for concrete block.

The downsides could be the additional build time that may be required because all of the factors that manufacture the material are located in the western U.S. That means the material has to be shipped by truck.