In your Edelweiss house you use 2x6 studs. Why not use 2x4 studs and add 2" rigid on the inside?
...2x6s, and would have been much thicker if the structure were made out of 2x4s. Designs with higher levels of glazings are often 2x6 for this reason. The best is to drop the large windows and go for smaller openings, but the building site was just begging for that sweet forest view in our case, so with the view and sol...