Hey Terry,
I have read George Swanson's book a couple years ago, and spent some time talking with him (listening to him) on the phone. A real wealth of information.
I saw somewhere in this thread that you mentioned someone getting a passivhaus certification with earthen walls. Did you ever get any more information about that by chance? Passivhaus is starting to gain some interest in my province. Ironically and unfortunately, it is about 40 years after it was essentially started here by a local engineer, Harold Orr. He is a great guy, retired now, but he would sometimes stop by the site of a rammed earth house I was building to see what was going on and to chat.
I am connected to a few of the main guys doing passivhaus builds and education in my area, but we are a bit at odds it would seem, as their focus is on air tight, ventilate, insulate like crazy, no matter what the composition of the materials being used, whereas I am attempting to use non-toxic, natural materials as much as possible (though I am still using cement until I can figure out how to incorporate MgO into the build). I like many aspects of passivhaus design, and would like to come up with a hybrid of sorts using earthen walls and many of the passivhaus standards, so if you had more information regarding that project, it would be greatly appreciated if you could share that info with me.
Thanks.
S