"legal duplex" vs. "non-legal duplex"

[Mike Purvis]

Hey guys,

I'm looking in the GTA for a duplex or a triplex. I see a lot advertised as a non-legal duplex but still advertised with multiple units. What are the legal issues of renting out a unit in your house when it's not legally a duplex or triplex?

How hard is it to turn a non-legal duplex into a legal duplex/triplex. How much does this cost in terms of fees from the city (ballpark)?

Thanks!