Concrete houses average a 30 to 80 percent savings in heating and cooling costs over conventionally constructed homes.  Virginia Power, a sponsor of this year's Homearama concrete house, offers its Energy Saver Home Plus program providing the homeowner with a 10 dollar credit on the bill each month for the first 10 years and a two-year comfort warranty, to qualifying homes.  The Homearama concrete house qualifies.

In terms of energy efficiency, the combination of concrete and polystyrene is hard to beat.  Measured in R-values, the concrete house is rated between R-28 and R-30 in the walls alone, according to Pocock.  A typical wood house has a rating of R-13.

Air infiltration, the rate at which outside air at ambient temperature, laden with dust, pollen, and pollution, enters the home, is 25 percent of what you get in a conventionally constructed house.

In industry jargon, the concrete house is a tight house.  It is so tight that industry standards recommend the controlled introduction of outside air through the HVAC (heating, ventilation, and air conditioning) system.  Pocock uses a high efficiency air-to-air heat exchanger that pre-heats or pre-cools incoming air.

"There's no such thing as a too-tight house," he says, "If you manage the inside air."

The concrete house is impervious to moisture and insects.  It is also fire retardant.  In case of fire, the materials in the walls do not emit the toxic by-products of combustion that occur in a conventionally constructed and insulated frame house.

Environmentally friendly, the principal constituents of the concrete house are portland cement, sand, and gravel, which are in plentiful supply.  No chlorofluorocarbons, believed to damage the earth's ozone layer, are used in the manufacture of the expanded polystyrene forms, so no potentially harmful residue is present to escape into the atmosphere.