duplex conversion to fourplex in Hamilton

[Maja D.]

Hi everyone, I put an offer on a legal duplex in Hamilton (just received a zoning verification certificate from city of Hamilton, confirming that the house is recognized as a 2 family dwelling, legally established non-conforming in zone C of Hamilton mountain area). This duplex has actually 4 separate units and 3 electrical meters, each unit has 2 separate entrances/exists. Previous owners apparently rented all 4 units and currently all units are vacant. It would be appreciated if someone can advise if it's possible to make this legal 4plex and from a legal perspective, what to expect if someone continues to rent all 4 units if it's recognized only as 2 family dwelling.

thanks