ICF technology is a leading green building method that combines multiple steps of conventional construction to build foundations and walls that are highly energy efficient, strong and yield a more comfortable and sound resistant interior environment. ICF construction began as a single-family residential foundation solution and has quickly gained market share in residential construction including multi-family units, low and medium rise residential construction and light commercial construction.
An ICF, which is the common acronym for insulating concrete form, is generally composed of two panels of expanded polystyrene insulation material that are held in place by a plastic bridging member across an opening or cavity that is most commonly 4, 6 or 8 inches wide. The ICF forms are stacked together to build a foundation or wall and rebar and concrete are placed in the cavity. The result is a wall assembly that has been independently tested to demonstrate energy savings on average of 44% less energy to heat the home and 32% less energy to cool the home.
The energy efficiency of an ICF is attributable to the continuous interior and exterior thermal envelope provided by the ICF, together with significantly reduced air infiltration as well as encapsulated thermal mass moderation. Thermal mass moderation means that heat is absorbed into the wall cavity and results in the ability of the wall assembly to smooth out large swings in temperature. It keeps the walls of the house warmer when the outdoor temperature hits its coldest extreme and keeps the house a little cooler when the outdoor temperature is hottest. In addition to the insulation provided by the high R-value in the EPS foam panels, an ICF works by reducing unwanted air infiltration across the wall assembly. This reduction in air exchanges per hour means that air is not constantly being exchanged and heated or cooled as is the case with conventional wood frame construction.