GlueGuy,
The only books I had on earth contact were written during the 1970's, so I basically took their insulation recommendations and then used more than I thought I needed. We have 3" of pink board to a depth of 6', then 2" to 10' and 1" for the remainder. The tricky part was remembering that around window openings, the 6' depth also goes sideways and diagonally, and UNDER the window. So, our main floor egress window in the bedroom has 3" of foam under it straight to the foundation. One rule I did pick up from the old books and have followed religiously is waterproofing. The best waterproofing is simply to give the water somewhere to go that isn't into the house. So, first we coated all exposed cement with Brewer coat. Then 6 mil Ag plastic wide enough to cover the entire wall and the footing. Then the foam insulation (which was temporarily held in place by wrapping duct tape around and around the whole house.) After that, I laid sock tube around the footing and about half way up the wall during backfilling. I also had a 4" slab put in the crawl space, with no drain line, so water can't back up. I'm still working on the backfill. It's about 1/3rd done. Basically, we had a small rise of about 3' and that's where we built the house. In order to earth contact, I have to build my own hill, which is made of sand and slopes gently away from the house. It's kind of like having a roof over the yard. By the time the rain comes off the house, lands on the hill, runs 14' to the edge and falls to the ground, it's far enough away to not cause any problems.
When I had my cement poured, I specified not only heights, thickness and window locations, but also pockets for the supporting girder and 6" PVC portholes. There's one for the well, one for the septic, 2 for cool tubes for additional crawlspace venting and one for a future outside wood burner. Before the backfill was done, I punched out the small PVC pieces the contractor had used to make these openings and inserted enough of my own PVC to bring tubes out 14-15' so I can dig em back up without moving a bunch of backfill.
I've heard about the dry lay up, but haven't seen anyone around here use it. Have you read Rob Roy's Cordwood Home books? He is a firm believer in the dry laid blocks, and most of his designs appear to be earth sheltered or contact.
SHF