So far very little has been written about earthbag basements. Earthbags are suitable for basements and other underground applications such as cisterns and rootcellars. Round or curved designs are inherently stronger than long, straight walls, which require reinforcing columns or buttresses.
Earthbag Basement Wall Detail
General guidelines for earthbag basements:
– 24″ wide poly bags (measured when empty)
– lime stabilized soil tamped solid
– 10%-20% type-S lime hydrate to dry soil by volume
– mix lime and soil thoroughly before adding water
– two strands 4-point barbed wire
– rubble trench with French drain
– taper walls slightly outward
– double layer 6 mil polyethylene moisture barrier
– use scoria, pumice, etc. for improved insulation
Build on high ground, and grade the site away from the building. Dry climates are obviously more suitable than wet climates. Use caution — working below grade is dangerous. Temporary shoring may be required. Avoid problem clay soils. The final design should be based on soil tests and calculations by a licensed engineer.
I have one plan with a basement: Habitat Earthbag House
Earthbag Building Blog 
Window wells can be incorporated to bring more light into the basement.
What is an earthbag exactly?
Most people think of it as a sandbag. We use the term earthbag because they can be filled with different kinds of fill material — earth, lava rock, etc.
hi
Im not sure about the size of the bags to use for walls and for basements, at my place its just easy to get 50cm wide (when empty), it is not to wide for a wall???
Most earthbag walls can utilize standard feed or grain bags about 18” wide when empty (close to 15” wide once filled and tamped).
Basements have to resist horizontal thrust of soil and so it’s better to use larger bags about 22” wide when empty (close to 19” wide once filled and tamped).
If I wanted to build a straight wall/square basement, how much more would it be compared to a round one?
How much are buttresses for basements?
And where can I read more about the lime and soil mixing?
Earthbag basements are very much experimental. No one has built one to my knowledge except for small survival shelters. Don’t attempt it without expertise advice, especially straight wall basements.
The military has tested lime/soil stabilization extensively. There are detailed reports on the Internet. It’s used for such things as rapid construction of airplane runways/landing strips. The experts are the Army Corps of Engineers.