I thought I could whip out a foundation plan in three days, but like the SIP structure, the foundation structure needs the approval of a structural engineer. There may be a loophole of some products, using a prescriptive method for insulating concrete forms in residential construction, but I’ll have to check with LA Building and Safety. It does look like I will have to visit the department with the drawing I have and ask for some advice.
I was planning on specifying the Nudura plank style ICF, but when I checked if it was still legal to use in Los Angeles, the company failed to renew their research report approval, and their product has lapsed. Since I have to start building in two or three weeks, I can’t wait around for them to renew. In the interim, I’ve discovered several other styles of ICF: block, panel, and plank. The material used to make the form can either be EPS or some hybrid or composite material (wood fiber and cement or EPS and cement).
I’m now steering this project toward a composite ICF, as only the stem walls of the foundation need reinforcement, and the larger EPS forms, though greater insulating factor, will not come off the ground much. The composite ICF that I like, is currently not approved in Los Angeles, but there are older styles that have gone through all the testing.