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Comment by fracus | Hacker News Reader

Did he "design" the building as in full schematics of a building that should stand? Or was this just a sketch in jest? I assumed we were reaching the limits of how tall we can make skyscrapers. Doubling the tallest ever built seems unachievable. Doesn't the square cube law bring it down?

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We're a long way from those limits. The limiting factor for tall buildings is elevators: The taller the building, the greater a percentage of the floor space gets taken up by elevator shafts. At some point so much space gets used by elevators that there's not enough rentable space left to make the building economically worthwhile.

It seems to me like elevator shafts with a single elevator going up and down is somewhat of a waste of building volume, with limited throughput similar to that of single-track railway.

Couldn't a smaller number of shafts move a greater amount of people using one-way traffic, paternoster-style?

Maybe, but there are details that matter that make it questionable. The Paternoster works but has both safety issues (thus illegal for new construction and where they exist only trained people are allowed to use it), and is slow. There are lots of other options that your elevator salesman can discuss with out - but all have trade offs that you may not like. In the end though there is no getting around large numbers of people take a while to move.

There are a few different systems out there, I haven't seen one in person, but they seem like interesting ideas. I found some searching "Circulating Multi-car Elevator System"

Historically, elevators hung on cables, and that's why it was one per shaft. Paternosters put more weight on their hanging parts and probably have much more severe height limitations.

We're slowly starting to see elevators without cables, and this will probably influence tall buildings in the coming decades. https://www.youtube.com/watch?v=EJLlXwVLDH0

> The limiting factor for tall buildings is elevators: The taller the building, the greater a percentage of the floor space gets taken up by elevator shaft

That’s only true if you plan for getting about everybody into and out of the building every day, at ground level.

There are some ‘designs’ (rather: rough ideas, typically in science fiction, and often dystopian) that let go of that constraint (think flying cars landing on balconies or enormous buildings where people mostly live and work on a few floors of an enormous building)

> That’s only true if you plan for getting about everybody into and out ...

> ... rough ideas, typically in science fiction, ...

Vs. in the real world: Fire Codes

Generally, fire evacuation doesn't count on using elevators anyway. Stairwells are used for evacuation. If the elevators still work, they're typically used by firefighters going up.

A lot of his buildings that were actually built were materialized sketches. Fallingwater was underbuilt, and Usonian homes are a bit awkward to live in because Wright glossed over important livability features.

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