> Interestingly enough, the huge outlier in slow construction isn't the US, but Canada, with an average skyscraper construction speed of half that of the US’s.

> Interestingly enough, the huge outlier in slow construction isn't the US, but Canada, with an average skyscraper construction speed of half that of the US’s. A building materials professor I knew years ago talked often about how robust Canadian skyscrapers were, and how many pre-9/11 U.S. designs never would have been approved there. I suspect differences in local building robustness code play a role in how much square footage makes it into skyscrapers in a locality, and how quickly.