Take a look at a post on You Tube called Thoreauvian Simple Living.
Though this shed, near my sister's house in far northern Maine is even larger than the house in the video, it is not as high. Still, at about 12 by 16, or more, it has plenty of space for a small habitation, summer cottage or studio. Notice that it is on pads, just concrete disks actually. As long as there is sheet metal underneath to keep vermin out and insulation, this is perfectly acceptable. The only other caution is that it must be on virgin, well packed soil, or on ledge. Digging below the frost line is always a good idea, so that frost will not heave unevenly and twist your house out of shape, but for this tiny house, with no plaster or plaster board inside, the risk is minimal, and correctable. Fragile but ridgid materials will crack with any movement, but tongue and groove boards will move with the foundation slightly. Just re-level the foundation, and it will slide back in place with only minor complaints.