Here’s an example or extreme prefab… pre-build the whole house and fly it in.
“In remote lake-and-hill country within Switzerland, building on site is often not an option – some spots are, at best, accessible only by motorcycle, small car or boat. This house was dropped off and installed in record speed.”
Read more about this Helicoptered Home: Flown Micro-Prefab Set Up in 5 Minutes | Designs & Ideas on Dornob.