Because they’re poor insulators of heat. Such a design won’t fly well up here in Northern WI where it’s single-digit temperatures and snowing.
Rammed earth houses are supposed to be good insulated houses.
So, I’m not sure if that’s a good reason. You can fill the inside of the blocks with insulating material or the inside side of the blocks.
I’m just curious, that’s all. I’m not that environmentally friendly. :)
Ever been in an adobe building in Arizona in the summertime?