There have been many variations on building houses with prefab forms, going all the way back to Edison. Works fine, but the result is a concrete box. The shell is not the big cost item in homes.
If you want a small, low-cost box structure, there are companies that will sell you one. Concrete.[1] Metal.[2] Steel frame with wood siding.[3]
If you want a small, low-cost box structure, there are companies that will sell you one. Concrete.[1] Metal.[2] Steel frame with wood siding.[3]
[1] https://precastbuildings.com
[2] https://www.butlermfg.com/
[3] https://www.homedepot.com/p/Rose-Cottage-2-Beds-443-3-sq-ft-...