Structural engineer, George Easton describes concrete building alike to assembling Lego blocks. "The "blocks" are polystyrene forms, called insulated concrete forms, into which the concrete is poured. The forms then are left in place to serve as lagging and the support for stucco on the external or drywall on the interior."
The walls can provide up to an R-50 energy rating and require approximately 44 percent less energy to heat and 32 percent less energy to cool compared to a customary wood home.