Alton we are going to have custom made EPS footing/slab panels; R26, 30 psi. This home is going to be in Vancouver, a temperate rainforest. So creating a passive house is something very possible. We are really looking forward to the project
ICF Hybrid. The largest footing you can do with an 8" wall is roughly 10x30". You are right, on wider footers the strongback can dig into the footing bag. For really wide footings, take a look what Robb Armstrong has done.
http://youtu.be/gD-rrgQcWpwThanks for the comments guys.