CMHC, Sagen and Canada Guaranty each insure mortgages under 20 percent down on a multi-family purchase the same way they do on a single-family home, and the minimum down payment rule, 5 percent on the first $500,000 and 10 percent above that, applies the same way too.
Get pre-approved specifically as a multi-family buyer before touring, since the rental worksheet and any required appraisal adjustments are sorted out during pre-approval, not after an offer is already written.
Joel Dyck can help you run the real numbers on a Lakeridge multi-family before you commit. Get your hand-reviewed valuation from Joel Dyck.