It is important to check whether there has been any Landlord and Tenant board claims prior to purchase and if the apartment is legal. If it is not legal you may have trouble insuring your property which is needed for your lender, and you may have to bring the apartment up to code at considerable cost to you. Find out first.

Here is a link to a detailed article by Joseph Richer in the Star.

http://www.thestar.com/life/homes/2015/04/10/do-your-homework-when-choosing-a-home-with-basement-apartment.html