Elevators create a particular problem. On one hand, adding more floors to the building will produce more space from which the developer can collect more money. But at some point, a new shaft and set of elevators need to be added to handle the additional traffic. This then eats into the rentable space….Do the additional floors on top generate enough rents to cover the loss of new space from the elevators?
…skyscrapers must devote about 30% of the total space to elevators, including their shafts, hallways and machine rooms.Via Alex Taborrok.
A technological breakthrough that could overcome this issue, it seems to me, would be an elevator that could "switch lanes" passing other elevators that are letting passengers in and out, or going the other direction in the same shaft, along the way.
But, as telecommunications and the Internet make location increasingly irrelevant, I'm not sure that there is enough of an economic incentive to develop that kind of technology.