Why not get just get an RV if you want it mobile. I can understand building a smaller house on a foundation if you are interested in less but if you're going to haul it around there is already something made that does that in an efficient way and I bet the price is about the same.
This:
https://www.tumbleweedhouses.com/wp-...-roof-hp-1.jpg
vs.
This:
http://www.cornerstonepref.com/corne...er-768x324.jpg