I think I saw this on r/financialindependence
It appealed to me since I don't have much construction experience. Seems simple enough to build. The foundation, or lack of, seems iffy though.
Popup Houses
http://www.popup-house.com/
Another Interesting Housing Concept
Re: Another Interesting Housing Concept
Looking at their website FAQ, they don't actually give a number on what they mean by "cheap" housing. While this idea seems interesting, it comes with some drawbacks, so it needs to be cheap period, not just cheap for a house.