Complex sentence: According to one estimate, building walls of ICFs adds $1 to $4 to this figure, but since ICF houses are more energy-efficient, the heating and cooling equipment can be up to 50% smaller than in a frame house.
Split into simpler sentences: According to one estimate, building walls of ICFs adds $1.00-$4.00 to this figure. But since ICF houses are more energy-efficient, the heating and cooling equipment can be up to 50% smaller than in a frame house.