I had the same vision, and looked into alternative building
materials--Rastra block (cement that is poured into foam molds, with rebar
inside--great to
cut heating and cooling costs), hay bale house (cheap, with the feel of adobe,
but beware of rats and mold if not done right), underground house (do this
right or you'll have problems similar to those in a basement).
I ended up doing standard but beefed up construction--4 X 6 wood, with
plywood covering inside and out, roof tiles nailed down, roof bolted to walls,
walls bolted to foundation--the same requirements as for hospitals and
schools.
We have our own well, our own solar power (partial only, as it is still
expensive, even with a government-supported rebate).
The hay bale idea sounded great, but I live in earthquake country. Rastra
was too expensive, and too difficult to make changes in electrical wiring once
it is up. With R-19 insulation in the 4 X 6 walls, though, we rarely use
air conditioning or heating (except for wood burning and pellet stoves).
Also,
dual pane window glass, with gas inside, cuts down on heating and air
conditioning costs, as do appropriate window coverings.
Don't underestimate the difficulty of getting anything unusual OK'd by the
planning department, unless you are planning to build without a permit. Also,
if you do anything out of the ordinary, you may have to do it yourself, as it
is hard to find someone to do anything but the usual standard stuff.
Jill
P.S. It turned out WONDERFULLY, but what an undertaking! I would only have
energy for this sort of effort once in a lifetime, though.
