Thanks for those links, Jenny O. I had no idea. I'd love to visit there.

Maybe during the "transition" everyone will go to a summertime work "day" from 9:00 PM to 5:00 AM.

I have some hillside property in Oregon that would be perfect for an underground or hybrid house. hmmmmm

In the US plains they built and used sod houses for quite a long time. What goes around comes around, I guess.