Thanks for all the responses so far.
greyskye-so far it's just dreaming, we still have a pretty big mortgage on our current house, so unfortunately we wouldn't be able to buy outright. However, it doesn't look like there are very strict building codes here (I'm in Saskatchewan, Canada), so we may be able to have some freedom even with the bank owning our house
Cob is a totally new idea to me - just heard of it for the first time yesterday. It's very intriguing, but I'm having a hard time finding internet info on how it would stand up to the harsh climate here, freeze-thaw cycles, very dry summers, etc.
Belleweather-passive solar is also a great idea. I don't know much about kit homes either, other than they're cheaper and more readily available than hand-designed log homes. Straw bale homes would be a concern because they're hard to insure, and dh is super-ultra-practical (an engineer) so that would never fly. I'll have to look into geodisk dome houses, don't know if I've ever heard of them before.
Bamboogrrrl-Thanks for the info. That makes me feel a bit better about metal roofs.
flutemandolin-that house sounds very interesting. Unfortunately the land is so flat here that the likelihood we'd even have a hill on our land is pretty low :LOL