I live in middle Tennessee and we are wanting to build an earth home. Been wandering around the forums and have seen people talk about  dry stacked surface bonded walls being cheaper to build than a monolithic poured wall. We want to do a PAHS Umbrella domed bermed home. How hard is it to get financing on this type of build? We will be purchasing the land with this build as well. Any info on this type of build in this area would be greatly appreciated.

Ok maybe this will be easier to answer after much research has went in today. I'm looking into building a 1500sqft walk out basement home. All one level with 3 walls buried up to 7 foot. I will do a slant metal roof that catches the runoff for use. Still have the issue of what would be cheaper? Formed poured walls or dry stack block walls?

Look in to ICFs. Much better wall than either plan poured or blocks.
Yes they will cost more up front. But the ROI from energy savings and COMFORT ain't bad.

I built a tire bale structure, and I am very, very happy with it.  In Tennessee, you could use vertical windows instead of the slanted variety.  It is a massive home, with passive solar and thermal mass providing greater than 95% of the heat.  The berming and outdoor shades really keep it naturally cool.  I'm in CO, and we have little humidity.  A dehumidifier may be needed in TN.

I posted a thread, with pictures, earlier on this forum.

I'd seriously consider that you can probably get better thermal performance (and resale value and livability) for less cost by building completely above ground (FPSF slab on grade).

If you must be underground, poured walls should be slightly more expensive but stronger than blocks.

I built a tire bale structure,

What about the alternative energy value of the tires you used? And, how does an underground tire bale structure compare in performance and cost to an ICF structure that is backfilled?