I have never seen a foundation poured like Lynn's. Very interesting to see different building techniques in different parts of the country.
Here, the footers would be minimum 18" deeper holes dug than the rest of the crawl space, then the footers poured into the holes. I have never seen footers formed before "above" grade. Understanding it's all down to virgin soil, so the effect is the same solid foundation.
Then, I've never seen the crawlspace come back and be poured to the footers (kind of upside down from what I'm used to seeing). Here, if it were poured, it would be done while pouring the footer and be basically about 4" deep even from the top of the footers in kind of a monolithic fashion. Still, really not any structural difference, just different look.
We would also put down plastic under it, but I assume that the climate is much more arid where Lynn is in Idaho, so probably not necessary there.
Lynn, thanks for sharing your build with us. These are my absolute favorite threads and I'm following with great interest. I'd love to move out West. My favorite part of the country.