Kit House

https://en.wikipedia.org/wiki/Kit_houses_in_North_America

These were available in the first half of the 20th century, but discontinued. They are replaced in the 21st century by shell home kits, and also some full kits.

Shell home kits do not include utilities, windows, doors, insulation, interior finish, foundation - just the shell: essentially walls and roof.

Examples:

• Shell home - [1]
• Complete kit - takes 6 months to build on nights and weekends - [2]
• Panel Home Kits - [3] - 2x OBI cost of 675 sf unit ($22k materials), but includes 2x4 framing instead of 2x6 and does not include: utilities, floor, foundation, roof material, interior finish, or exterior wall finish. Requires crane.
• Shell structure - [4]
• Owner-build Shell Kit - [5]
• This one says it's the real thing - [6] - starting at $107k, 350 sf

Links

• Mother Earth News - guide to kit houses - [7]