I found the idea on calearth.org and it seemed like the best way to go as far as strength, low price, insulation, ability to withstand various kinds of disasters. Such as: fire, tornado, heavy rains, lightning and so on.

I am building it in Ozark County in Southwest Missouri. An ideal location since there are no building codes or permits required here which saves on lots of red tape an money. The only unfortunate here is I have to pay to have sand trucked in but it's a minimal cost as compared to building the same amount of square feet in traditional housing or even modular or mobile homes.

I am starting by adding an art studio / furnace room on to my existing mobile home. Once I ad on a few rooms this way, I'll start removing existing rooms from the original mobile home and replacing them with sandbag rooms until the entire structure is sand bags encased inside and outside layers of concrete.

I am pretty much experimenting as I go but so far everything has started out well. I put down the first few rings of bags on a slight slope. More bags deep on the downhill side of course. In between each layer of filled bags is two parallel rows of 4 prong barbed wire to
eliminate lateral shift.

I attended the Monolithic Dome School (monolithicdome.com)but sand bags seemed to be less expensive. Lower tech and when people show up to help me, they need minimal if any skill. If they can fill a sand bag and carry it and stack it on the others, they are skilled enough to help.
So far I have done most of the work myself with a few hours help from my 12 year old son and a buddy of his.

I also have another project called "The House That YouTube Built" In that project a bunch of us from all over the country are getting together and building a free house for a needy family and filming the process as well. Anyone wanting to get involved can search The House that youtube built on youtube.com or search thechurchofdave on Google
until you find my home page an from there you can find the house project.

Sincerely
DAve