Earthbag questions

I plan to build an earthbag home in north Texas. One of my concerns is that this is a tornado prone area. Another is heat. I think the earthbag walls will provide enough mass to resistant to tornados and keep it cooler but I'm also thinking of reinforcing it by berming around three of the walls. Obviously I have waterproofing concerns with that but I think they can be worked through pretty easily. Do you think it is necessary to berm for tornado proofing? How much will that help with the heat? Another concern regarding tornados is the roof. I would love to have about 3 feet of dirt on the roof but I don't think I can build a structure capable of handling the weight. The house plan is around 1800 SF. The interior walls are also earthbag but I still think the spans are way too big for that much load. Is there a way to basically put anchors into the ground and "tie-down" a more traditional roof? Berming might actually help with this. Not sure how feasible this is though. Any thoughts would be appreciated
Blake

Howdy Blake, welcome to permies!
I don't have any answers so I thought I would bump this back to the top.

Thanks, Miles. It looks like a great community!

So I'm still curious about all of this but I have an idea that may work for the roof. I'm still wondering if anchoring it the way I described before would work. If not, I'm thinking about building a heavy, metal-framed roof and welding it to support poles that run down into the ground. I would then build the earthbag structure around those poles. That seems like it may be overkill but I want to make sure this is permanent. Cost might be a major factor with that idea though. Any other ideas?

For all earthbag housing questions please talk to
www.calearth.org
These are the people that REALLY know the answers!
Their founder developed the process and they have a
demonstration site in Hesperia, CA as well.