another way to get around that dreaded thermal bridging is to build a 2x4 wall on a pair of 2x8 plates. stagger the studs, so that the only locations where a stud passes from inside to out is @ doorways and windows.
In the mid-late 1980s, when I was a carpentry student at the local trade school, we built a "Good Sense Home" that was auctioned off at the close of the school year. It had two 2X4 walls set on a 2X12 shoe/plate that had a small air space in between. Deep window sills by default.
Both walls were insulated and stud layout staggered. The local power company (Central Maine Power) had sponsored these. Electric heat was becoming popular. We had a nuclear power plant then. It was the only example I ever saw of this type of "super insulated" house. I don't know why it didn't become more popular.
