What is the most efficient walls for the southwest?

Question:R-Value?
Labor?
Cost?

Answers:
The the wall type with the highest R-value to cost ratio is hay bale construction. The BIG drawbacks are thickness of the walls, difficulty in getting attractive wall finishes and getting approvals from local building departments.

There are a lot of web site with information on this type of construction.

http://www.greenbuilder.com/sourcebook/s...
http://www.balewatch.com/technique.html...
http://www.strawhomes.com/