[FiatLuxDave]

I like this answer, because you have put some thought into this. I would add to your idea these things: a) all components are "man-portable", so that they can be put together by people without the use of cranes or heavy lifting equipment (this is a big deal in construction), b) have external mounting points so that they can be attached firmly to a building skeleton, allowing for building out a skyscraper using only manpower once the skeleton and elevators have been put up.

I will say that here in the South, we have a similar product which is located in "trailer parks". It is worth looking at the failures of the existing trailer parks when looking at ways to make cheaper housing.