Duplex Mortgage Guide for Ontario Investors — Rates, Down Payments & Lender Rules

Owner-Occupied vs Investment Property: Two Very Different Rules

The most important distinction in duplex financing: are you living in one unit (owner-occupied) or not (pure investment)? Owner-occupied duplexes qualify for residential mortgage rules: minimum 5% down with CMHC insurance, access to First Home Savings Account funds, and lower rates. Pure investment duplexes require minimum 20% down, higher rates, and stricter rental income qualification rules.

How Lenders Include Rental Income

For owner-occupied duplexes, lenders typically include 50–80% of the rental income from the second unit in your qualification. This can significantly increase your borrowing power — sometimes by $80,000–$150,000. For pure investment duplexes, lenders use a 'rental offset' approach: they subtract the rental income from your carrying costs rather than adding it to your income. Different lenders treat this differently — which is why working with a mortgage broker who specializes in investment property is essential.

CMHC Rules for Duplexes

CMHC (Canada Mortgage and Housing Corporation) insurance is available for owner-occupied duplexes with less than 20% down. The premium ranges from 2.80% (20% down) to 4.00% (less than 10% down) of the insured amount. Key CMHC rules: maximum purchase price of $1,500,000, minimum credit score of 600, and the property must be a legal duplex (CMHC will verify). CMHC does NOT insure pure investment properties — you need 20% minimum.

Which Lenders Favour Duplexes

Not all lenders treat duplexes equally. Monoline lenders (who sell through mortgage brokers and don't have retail branches) often offer the most competitive rates for investment duplexes because they specialize in this product. Big banks (TD, RBC, BMO, Scotiabank, CIBC) are more conservative and often use lower rental income offsets. Credit unions can be flexible — some will use 100% of rental income in qualification.

Rate vs Terms: What Actually Matters

Investors often focus exclusively on rate. But for duplexes, the mortgage terms matter enormously: prepayment privileges (can you pay down extra principal without penalty?), portability (can you move the mortgage to a new property?), and rental income treatment (does this lender give you full credit for your rent roll?). A mortgage that's 0.2% higher in rate but allows unlimited prepayments might save you significantly more over a 5-year term than the lowest-rate option with a closed prepayment structure.

Educational purposes only. Not financial, legal, or investment advice. Always consult licensed professionals before purchasing.