I mentioned ICF in a prior post as the technique we have settled on for building our basement walls. What I did not mention was that initially we had also planned to build all the walls with ICF. We changed to using 2×6 framing based on various green/passive building techniques we had been reading about.
However we have recently been considering whole house ICF again. This is due to the price of lumber skyrocketing in the US currently. Generally building your entire home with ICF instead of traditional wood framing adds about 3-5% to the overall bill. Currently lumber is about 30%+ up in price so that 3-5% is pretty much wiped out. Add to that the extra costs we were going to incur with spray foam insulation and external continuous ridgid foam insulation and ICF is looking pretty nice.
Beyond the economics though an ICF house has major practical benefits:
- The walls are self standing. This allows the roof to be built in different manners since it is independent of helping support the walls. You can even use ICF for the roof.
- Sound proofing. A solid concrete house is very quiet.
- Thermal bridging. Since the concrete is solid all the way around and the insulation is built in there is no thermal bridging, which is a fancy way of saying that wood studs suck at insulating.
- Bullet proof. I really hope we never have to test this but if it comes to that we will have a fortress in which to ride out the apocalypse.
- Build time. With ICF you build the form, pour the concrete, and the walls and insulation are done. Then its just roughing in electrical and plumbing and adding the finish.
We have gotten some quotes from ICF suppliers. Now we are talking with installers and getting quotes. The fun never stops apparently.