What an interesting read. I've got some friends who amazed me at the efficiency gains of their fully-off-the-grid house in the Texas Hill Country. It's so well-insulated that a single tiny window AC unit keeps the house pleasant on 100+ degree summer days.

One danger of super-insulating is the corresponding super-sealing of various gaps and cracks in homes that allow air to escape. When building super-insulated, highly efficient spaces, it's critical to consider ventillation (both intake and outflow) much more than we've historically done. A worthwhile read on all of this BTW is McDunough's "Cradle to Cradle" book.