Roof PSF CHICAGO New Construction roof deck

[Christopher Bell]

I’m looking at a property where our offer was accepted. I’m really excited, this is my fiancé and my first property. I was talking with a coworker and he mentioned that it may not be that easy to build a roof deck even though we have roof rights. Something about a CHICAGO law that has a waiver from 2003. Is there a way to look up my roof’s current pound per square foot that can be built? Is there a way to increase PSF that’s available?