1) What are some of the ways the three people increased livable space while using little actual space?
Instead of doors that open up, they use sliding doors.

2) Would one solution work better in certain situations? For the three, where would this solution be best implemented?

The appartment would work the best.
3) If you owned one of these dwellings, which would you live in? Why?

The third one. I like the design of the appartment.