Hummingbird: Insulated
From the Ground Up

The foundation of the Weingartens' house is not your typical one. Special forms, called ICFs -- insulating concrete forms, were used to hold the concrete, which was mixed on-site to ensure proper hardness. It took over 90 yards for the entire house -- up to three trucks at a time in tight quarters. The Weingartens added two inches of foam to the outside of the insulated forms, as well as the slab, just to be thorough.

The reason for the insulation is to create a tempered space beneath the house instead of a cold space, so that it makes it easier to keep the house at the desired temperature.

You'll be able to see the progression, from bare dirt to concrete-pouring, in the slide show above.