Straw is biodegradable in the presence of moisture. The steel container next to the straw will condense moisture onto the straw and it will rot. Stawbale construction requires walls that encapsulate the straw be made of breathable material, such as plaster. You could use containers for the load bearing structure but you'd need to get artistic with a torch and scallop the container walls so that the straw would be exposed and plastered. I think a post and beam wood structure is easier. Alternatively, you could join containers side to side to get volume, and then put the straw on the inside with a vent wall between the straw and the inside container wall to get rid of moisture and isolate the straw from the steel. You would vent to the outside, top and bottom holes in the container several places. Build a 4x4 base for the straw and fill with pea gravel. Put rigid foam on top of the bales to isolate from the roof.
