Our earthbag projects have confirmed what I’ve known for a long time – that building at $10/sq.ft. (materials only) is possible. Other aspects of earthbag building — strength, durability, sustainability, etc. — are all important. But perhaps the most important point is affordability, because building at $10/sq. ft. makes housing affordable to virtually everyone on the planet.
Are you on an extremely tight budget? (Ha, who isn’t nowadays.) Then I suggest building small using local natural materials, building in stages and adding on as you can afford it. For instance, build one roundhouse and live in it until you’ve saved enough to build another. You could join the roundhouses with arched or gabled covered walkways, enclosed passageways or additions, or just leave them free standing. Extending rectilinear structures would be even easier. Adding on like this requires planning for future doorways and other considerations, but this approach allows you to build debt free.
Here’s a brief list of some other projects built at or near $10/sq. ft (scroll down a little).