This seems wrong... are people opening windows on the 60th floor? What about those buildings whose design precludes easy retrofitting to openable windows? I'm not being rhetorical, I'd like answers.
The residential stories have casement windows, within the curtain wall, that can swing up to 4 inches (100 mm) outward. In addition, some condominium units have motorized windows at least seven feet (2.1 m) above the floor.[1]
The condominiums start on the 32nd floor, according to the same article.
If building can't easily be retrofitted to allow openable windows, then I would assume they either can't be used for residential or they could try to get some sort of exemption if they can prove it's safe. I'm mostly going off what I know about building codes and what I've read previously on the topic when it's posted and it's delved into what the actual problems are in converting to residential.