Freshwater, sewage, fire codes, elevators, foundations, load-bearing structures, HVAC all get more difficult as you add more floors (beyond some small number ar

Freshwater, sewage, fire codes, elevators, foundations, load-bearing structures, HVAC all get more difficult as you add more floors (beyond some small number around 4 where it's all pretty trivial). Another advantage 5-over-1s have (which the NYT article also mentions) is that they are cheap and easy to build. Very tolerant to cheap building materials, lots of prefabricated parts, lots of contractors who are familiar with how to build them. And because there's more demand then supply and people mostly pay based on location there's little incentive to do something more expensive