I have wanted to create a couple of houses on wheels, but big enough to be hauled by a truck that can handle the weight I would have in one of mine that is built from all vintage lumber. Using doors, windows, flooring, and all the same materials that I use to create great houses, we could outfit and modify semi trailers so they could be moved without special size permits and pop out, drop the axels and tires, and leave the anywhere in the USA. This would dramatically change shipping costs and the possible layouts of houses, as well as the future of the old trailers as they are taken off line and trashed normally.
If you use refrigerated trailer units you can get a 3 cylinder diesel motor with an air conditioning system that will also act as a power source for a generator if you need one. If you buy at the right price, you may make the money back off the axles and the refrigeration system. This is for the bold to consider who are willing to push the boundaries of what we can do with salvage trailers, as well as houses to create more ways of manifesting affordable portable housing. Build it where the labor and salvage materials are cheap and send them around the country to where there is more profit to be made.
If you are interested in pursuing this idea and adventure, contact BWK@tinytexashouses to get on the list of those who might like to be part of the construct and design, as well as the build out we will do on one when we have enough people to pull it off.