There's an economic problem with well made smaller homes - they have all the detail of a larger home without the square footage. Hence the cost per square foot is much larger than you would expect.
This ! What I learned during the construction of my home is that the structure is really only one part of a construction. It’s a lot of raw material of course, but relatively cheap one and the construction of the structure is pretty fast. What takes months and a lot of money is just everything else : networks, windows & doors, walls, finishing …
I’m in the middle of trying to figure this out with a friend by building an off-grid tiny house and this is pretty accurate. With our labor at a nominal rate (30/hr) it’s coming out to about $250 per square foot. We think on the next one we might be able to get down to $200 maybe $175.