Earthbags have proven to be incredibly versatile. They can be used throughout your home for foundations, walls, benches, privacy walls and other uses. And let’s not forget about stairs. Think how much money you can save by using earthbags to build your stairs. And they’re sturdy, too. Here’s a picture of curved stairs.
In the house I built in Colorado I made a similar earthbag staircase to access the loft in the bedroom. It not only served this function, but also provided a giant thermal mass in the room to help maintain a comfortable temperature there. I had plastered the bags with papercrete, which turned out to be too soft to wear well with the treads, so I would recommend a more durable cement-based plaster for this. Here is a picture of that staircase.