Basically, what has been found over the years, is that the homes work well if the logical instructions contained in the book Passive Annual Heat Storage, Improving the Design of Earth Shelters is followed. Otherwise things don't always work out so well. The book is available from this web site.
Still, the most advanced book available on the subject is Passive Annual Heat Storage, Improving the Design of Earth Shelters. This 1983 text is still quite up to date as it teaches the basic methods of understanding natural heat flow methods that never change. Other supplementary materials, home plans and instruction videos are available.
You can order books, videos, and papers on a large variety of topics which are available from the Rocky Mountain Research Center.
