"Legal Non conforming use" help

[Joseph Berdugo]

Hi my name is Joe and I'm new to biggerpockets. I'm buying my first house which is a 2 family house and I'm very excited, but I do have a concern. I just got my appraisal back a Hi my name is Joe and I'm new to biggerpockets. I'm buying my first house which is a 2 family house and I'm very excited, but I do have a concern. I just got my appraisal back and I noticed that in the section where it mentions the zone, they call it a R2 which I understand it to mean a 2 family residential zone. The next line though mentions that it's a "legal non conforming (grandfathered use)". Now one of the reasons I like this house is because of its larger than average lot size in jersey city and the idea that someday I might be able to convert it into something bigger, say a 4 family house. But the term, "legal non conforming use" seems to indicate that I might be limited in what I can do with it. It might even take away from what I have right now, for example if I decide to demolish the old structure and rebuild it from scratch I might not be able to do that. How do I know what I'm getting into? Thx Joen