Legal non conforming zoning help

[Joseph Berdugo]

Hi everybody, My name is Joe and I'm new to biggerpockets and I just love the info that's available on this website. So that said, I'm buying my first house in Jersey City which is a 2 family house and I just got the appraisal and it mentions that the house is a R2 zone. Right after that it says that it's a legal non conforming (grandfathered use). I like the house because it sits on a large lot (42 X 90) and my thinking is one day I might be able to convert it something bigger, say a four family or more. My concern is that a legal non conforming use someday, might limit or even detract from what I can do with the property. How do I know what my limitations are? Thank you in advance Joe