Residence Performs Double Duty As Green, Dream Home

A 9,200-sq.-ft., Prairie Grove, Ill., residence provides an example of prefab concrete construction that boosts the performance of homes with respect

A 9,200-sq.-ft., Prairie Grove, Ill., residence provides an example of prefab concrete construction that boosts the performance of homes with respect to sustainability and energy efficiency, plus resistance to fire, storms and mold or insects. Use of the Solarcrete system to build the Smith’s home is described in Prefabulous Û The House of Your Dreams Delivered Fresh from the Factory by author Sheri Koones, who showcases the technology as a sustainable construction method that provides both structural benefits and aesthetic versatility. In general, Koones touts the advantages of prefab building systems to meet green building objectives by making homes stronger, minimizing construction waste, boosting energy efficiency, and reducing demand upon material and labor resources.

Regarding the use of concrete in residential construction, Koones notes significant advances over the last decade: approximately 3 percent of U.S. homes were built using concrete panels in 1993, while today more than 10 percent of homes use some type of prefab concrete system. [Concrete’s] popularity is growing because it is plentiful, easy to create in a variety of colors and in a multitude of forms, is virtually weatherproof and bugproof, and when reinforced with steel is strong enough to stand up to hurricanes, tornadoes and earthquakes, she writes, adding that the material’s thermal mass and airtight qualities also provide a high level of energy efficiency.

The Solarcrete panels used in the Smith House contain a core of 7-in. expanded polystyrene insulation sandwiched between two parallel sheets of wire mesh or reinforcing bars held together with ties. Pre-engineered at the plant, the panels are transported to the site and attached to the foundation via steel dowels cast into the structure. Before a 3-in. concrete layer is sprayed onto each side of the panels, spaces are cut out for windows, doors and plumbing, and wires are snaked through the foam insulation, Koones explains. Troweling creates a smooth surface finish after concrete is applied. The roughly 12-in. wall constitutes an insulating envelope whose thermal mass serves to even out temperature fluctuations.