Japan is a small country. And Japanese is good at squeezing a lot of things in a small place. (Look at all these amazing Japanese inventions from the past.) This analogy also applies to a house.
Yamada SxL Home, a mid-size home builder, launched a brand yutoRino. This series allow building 3 story house with a minimum land plot width of 3.7m. (Setback needs to be accounted as an extra width.)
For instance, this typical plan spans the 1st floor to be 36.77SQM, 2nd floor: 35.28SQM and 3rd: 35.28SQM – the total of 107.33SQM. (It also comes with a tiny garden.)
(Images: Yamada SxL website)
The construction cost – in a case of GFA 46 tsubo or (151 SQM), it is JPY 660,000/tsubo or JPY 20,000/SQM.