Capital Gains Tax on Selling a Duplex in Ontario — What You'll Owe and How to Reduce It

How Capital Gains Tax Works on Real Estate

When you sell a property for more than you paid, the profit is a capital gain. In Canada, a portion of that gain is included in your income and taxed at your marginal rate. The 'inclusion rate' determines what portion is taxable. For individuals, the inclusion rate has historically been 50% — meaning if you made $200,000 on a property sale, $100,000 was added to your income. Recent federal proposals have discussed changes to this rate — consult your accountant for the most current rules before planning a sale.

The Principal Residence Exemption — Partial Application for Duplexes

If you live in one unit of your duplex as your principal residence, you can claim the principal residence exemption (PRE) on the portion of the property you occupy. This is typically calculated as a fraction of the property (e.g., if you occupy 50% by floor area, you can exempt 50% of the capital gain). The rental portion cannot be exempted. This is why keeping detailed records of which portion you occupy — and for how long — is important for eventual sale tax planning.

CCA Recapture: The Hidden Tax

Capital Cost Allowance (CCA) is tax depreciation on the building portion of your investment property — a tool your accountant may have used to reduce your rental income taxes each year. When you sell, CCA you've claimed is 'recaptured' and taxed as regular income (not at the capital gains rate). If you've claimed $30,000 in CCA over 5 years, that $30,000 is recaptured as ordinary income in the year of sale. Many landlords are surprised by this — plan for it well in advance.

5 Strategies to Reduce Your Capital Gains Tax

1. Use the principal residence exemption for the years you lived in the property. 2. Stop claiming CCA in the year before sale to reduce recapture. 3. Time the sale to distribute the gain across two tax years (close December 31 vs January 1). 4. Donate a portion of proceeds to charity for a tax credit (limited but effective). 5. Consider a Section 85 rollover if selling to a corporation (consult a tax lawyer). None of these should be executed without advice from a tax accountant who specializes in investment real estate.

When to Talk to Your Accountant

Before listing, not after. Capital gains tax planning is most effective when done 6–12 months before a sale. If you wait until after closing, most opportunities to reduce your tax bill are gone. Request a pre-sale tax analysis from your accountant — many offer this for $200–$500 and it can save multiples of that amount.