Hey Cyndy,
I love building with curvy earthbag walls and sculpted ferrocement roofs, or EB dome. But its a lot of work, and I'm half your age, and I don't have the patience for cob, and I don't have money to build with convenience materials. Yes you can use use earthbags as foundation for a cob building,with gravel bags a great choice as to not wick up moisture. And Owen always praises cylindrical roundhouses for ease of construction.
But on the other hand you have a fskilled framer husband with a construction workers back. How about rammed earth, straight walls, easily insulated? Hire a neighbor with a
tractor to mix, move and dump
bucket loadsinto slip forms. Could tamp with bucket or rent a tamper. I know you have great soil close by. You also have cheap limstone sifted aggregate that could be mixed with clay (tractor auger mixer anyone?). That goes quick and easy on the body. Or strawbale. Easy to roof and inhabit straight walls.. Thermal mass is awesome. If you use wood, make sure you have a good termite barrier in place down there.
I love the loft in my dome, but Do you really want to climb into a loft as you get older, carrying things up and down? Or do eb/FCfc high up in the air? I also love doing sculptural ferrocement roofs, but your husband is a framer. What about all those cedar and pine out there for the roof? Timbers and rough sawn are cheap and
local. Find a local mill. Get grade 2 if you have no budget. Then he doesn't need to learn about catenary, ribs, how to plaster a ceiling, ferro lamination, structural engineering masonry roofs etc. a conventional roof shape will blend into the cultural environment better, and address your rains and shading needs easier too.
It's great that y'all won't start for a year. That gives you time to think, discuss and evolve your plans and to See what's local,ly available, what materials pop up in the paper, etc. have fun and choose something that won't wear out your backs. I've seen people your age build slooowwly because of the labor involved in natural building, but there are approaches so as not to haul buckets all night long. I think you can both design a beautiful natural home while your husband can shine framing sustainably.
And you don't have to mention the low income, this is the earthbag forum
but do consider your time in a dirty cheap construction approach
Chris