[wahern]

Maybe I'm overthinking it and/or maybe the article is using an idiosyncratic meaning of "foundation". The article says "The foundation of the Tiny House uses cantilevers, seesaw-like joists that help save wood and concrete and actually make the house stronger than a typical foundation would." Which might be a fancy description for basic techniques[1] used to build countless old houses in Alabama and elsewhere, some of which I got to crawl under or around when working summers with my Dad, who did remodeling and other contractor work in Alabama, Florida, and Louisiana. Not all those houses had footings directly underneath the permitter; the joists and walls might cantilever, while the footings were still basic and not tied together like with the cantilevered footing system. Although the cantilevers might be more extreme in these new designs.

Unfortunately, I can't find any technical material on the school's website. Here's the page for the various homes: http://ruralstudio.org/project_tags/20k/. Notably, some of them do seem to use modern concrete slab foundations, and at least one of the pictures shows a bulldozer in the background. Looks like they have a bunch of different designs.

[1] Basically just like people build decks today. Of course, lots of decks are dangerous, shifting and collapsing, precisely because the techniques aren't very forgiving of mistakes or poor siting.

EDIT: Here's a blog post with a better description, which seems to be discussing the same house(s) depicted in the Fast Company article: "Siteworks are a major cost item and cantilevering the floor joists past the foundation piles reduces the area of siteworks. ... Cantilevered floor girders act more efficiently as beams, making smaller and less expensive timber sections sufficient. Floor joists are cantilevered from the girders for the same reason." https://misfitsarchitecture.com/2016/08/31/architecture-misf... So it seems the usage of "foundation" in the other article was misleading. And these definitely aren't new techniques, not if you count the stock of 50-plus-year-old homes built in poor, rural America (i.e. not simply the stereotypical New England farm house). So presumably what's innovative is that the students have done the proper analysis and testing to refine them, ensuring they behave as intended as well as meeting modern standards of safety and reliability.