I believe the combination of these two building systems has some amazing advantages: Earth-bags need some type of foundation, whether rocks, concrete, or pounded tires. Building the entire wall of tires, however, takes a lot more effort than superadobe, and is more time-consuming due to leveling, picking the right tires, etc. Also, including a greenhouse (depending on the climate zone) makes a lot of sense in terms of temperature regulation, and food production.