- Insulation aka "R Value": ICF walls have a huge R value, typically four to five times higher than a stick frame wall insulated with R-11-rated insulation.
- Thermal Mass: Concrete is incredibly dense, thermally-speaking, and thus the walls of your house act as a giant heat sink, meaning daily changes in outside temperature have little effect on the inside of your house. This winter, while researching all this, I stood in the basement of an ICF home that was being built. The home had been "air tight" since fall, but there is still no HVAC installed by mid-winter. Even though it was below 0F outside, the basement still felt rather warm, probably 50F. All this from just insulation and thermal mass.
- Peace and quiet: ICF homes are incredibly sound-proof. Enough said.
- Structural strength: ICF contractors have shown me pictures of ICF homes surviving tornadoes that completely destroyed all the stick frame homes around it, and also ICF homes that survived Hurricane Katrina largely unscathed. Nothing beats real-world testing! In test labs, ICF walls survive TNT blasts and 180-360 MPH wind speeds, depending on design.
- Operating Cost: Because of the above benefits (and others), ICF homes are cheaper to insure, and much cheaper to heat and cool.
- Construction cost: ICF homes do typically cost a bit more to build than stick frame homes, though it seems this varies a lot by builder. This is why I'm taking my time and shopping around to find the best deal.
- Selection: Most general contractors either don't know what ICF is, or don't want to learn how to build houses with ICF walls. Definitely do not be a guinea pig for a contractor who has never done it before. Make sure they have built at least six ICF homes already!
