Duplexes are one of the best entry points into Canadian real estate investing — live in one unit, rent the other, and let your tenant help pay your mortgage.
Types of duplexes
| Type | Description | Common In |
|---|---|---|
| Side-by-side | Two units share a centre wall; each has its own entrance | Ontario, Prairies |
| Stacked (up/down) | One unit on top of the other; separate entrances | Montreal, older urban areas |
| Converted house | Single-family home converted into two units | Everywhere (with proper permits) |
| Purpose-built duplex | Designed and built as two units from the start | New construction |
| Semi-detached (sometimes called) | Two separate addresses sharing a wall — technically two separate properties | Ontario |
Note: A true duplex is one property with two units. A semi-detached is two separate properties that share a wall.
Duplex investing: the numbers
House hacking example (owner-occupied)
| Item | Amount |
|---|---|
| Purchase price | $650,000 |
| Down payment (5%) | $32,500 |
| CMHC insurance | ~$24,700 |
| Total mortgage | ~$642,200 |
| Monthly mortgage (5.5%, 25yr) | ~$3,940 |
| Property tax | $400/month |
| Insurance | $200/month |
| Maintenance reserve | $300/month |
| Total monthly cost | $4,840 |
| rental income (other unit) | $2,200/month |
| Your net housing cost | $2,640/month |
The rental income covers ~45% of your total housing cost.
Pure investment example (non-owner-occupied)
| Item | Amount |
|---|---|
| Purchase price | $650,000 |
| Down payment (20%) | $130,000 |
| Mortgage | $520,000 |
| Monthly mortgage (5.75%, 25yr) | ~$3,270 |
| Property tax | $400/month |
| Insurance | $200/month |
| Maintenance | $300/month |
| Management (10%) | $440/month |
| Total monthly cost | $4,610 |
| Rental income (both units) | $4,400/month ($2,200 × 2) |
| Monthly cash flow | −$210 (slightly negative) |
Even at a slight negative cash flow, the equity buildup (~$1,200/month in principal payoff) and appreciation make it a wealth-building investment.
Financing a duplex
| Scenario | Down Payment | CMHC Insurance | Rate | Rental Income for Qualification |
|---|---|---|---|---|
| Owner-occupied (live in one unit) | 5% minimum | ✅ Available | Standard residential | 50%–80% of other unit’s rent |
| Non-owner-occupied (investment) | 20% minimum | ❌ Not available | +0.10%–0.25% premium | 50%–80% of both units’ rent |
| Duplex over $1,000,000 | 20% minimum | ❌ Not available | Standard + possible premium | 50%–80% of gross rent |
How lenders use rental income
| Lender Approach | Calculation |
|---|---|
| Rental offset (most common) | 50%–80% of gross rent reduces your housing costs in GDS/TDS |
| Add-back method | Add 50% of rent to your income |
| Net rental income | Gross rent minus 50% vacancy/expenses = net; added to income |
Zoning and legality
Is your duplex legal?
| Factor | What to Check |
|---|---|
| Zoning | Is the property zoned for two units (R2 or equivalent)? |
| Building permits | Was the second unit built with proper permits? |
| Fire separation | Adequate fire-rated separation between units (1-hour minimum) |
| Separate entrances | Each unit must have its own entrance |
| Separate services | Ideally separate electrical panels, water heaters, HVAC |
| Parking | Many municipalities require 1+ parking spaces per unit |
| Non-conforming | A duplex may be legal but non-conforming (existed before current zoning) — still legal but restrictions on changes |
| Illegal suite | If converted without permits, the second unit may be considered illegal — insurance and liability issues |
Provincial secondary suite legislation
| Province | Status |
|---|---|
| Ontario | Most municipalities now allow secondary suites as-of-right (provincial legislation) |
| BC | Secondary suites and laneway homes broadly permitted in many municipalities |
| Alberta | Varies by municipality — Edmonton and Calgary have expanded permissions |
| Quebec | Duplexes are very common — zoning generally permissive in urban areas |
| Manitoba | Varies — Winnipeg has expanded secondary suite allowances |
| Atlantic | Increasingly permissive as provinces address housing supply |
Converting a house to a duplex
Steps
| Step | Details | Cost |
|---|---|---|
| 1. Confirm zoning | Check with your municipality — is a second unit permitted? | Free |
| 2. Hire an architect / designer | Create plans that meet building code | $2,000–$8,000 |
| 3. Apply for permits | Building permit, plumbing, electrical | $500–$3,000 |
| 4. Fire separation | Install fire-rated drywall/doors between units | $3,000–$10,000 |
| 5. Second kitchen | Full kitchen in the new unit | $10,000–$30,000 |
| 6. Second bathroom | If not already existing | $8,000–$20,000 |
| 7. Separate entrance | External door if not existing | $3,000–$10,000 |
| 8. Electrical | Separate panel for each unit (or sub-metering) | $3,000–$8,000 |
| 9. Egress / safety | Egress windows, smoke alarms, CO detectors | $1,000–$5,000 |
| 10. Inspections | Municipal inspections at various stages | Included in permits |
| Total estimate | $30,000–$100,000+ |
Pros and cons of duplex investing
| Pros | Cons |
|---|---|
| ✅ Rental income offsets mortgage | ❌ Tenant management responsibilities |
| ✅ 5% down if owner-occupied | ❌ Shared property — less privacy than detached |
| ✅ Two income streams (lower vacancy risk) | ❌ Maintenance costs for two units |
| ✅ Build equity while someone else helps pay | ❌ Proximity to tenants (if house hacking) |
| ✅ Strong demand in most markets | ❌ Zoning restrictions in some areas |
| ✅ Appreciation + cash flow | ❌ Insurance is more complex/expensive than single-family |
| ✅ Stepping stone to larger multi-unit | ❌ Potential for problem tenants |
Duplex prices by market
| City | Avg. Duplex Price | Typical Rent (per unit) | Potential Gross Yield |
|---|---|---|---|
| Toronto (GTA) | $800,000–$1,200,000 | $2,000–$2,800 | 4%–5.5% |
| Montreal | $500,000–$800,000 | $1,200–$1,800 | 4.5%–5.5% |
| Ottawa | $550,000–$750,000 | $1,600–$2,200 | 5%–6% |
| Calgary | $400,000–$600,000 | $1,400–$2,000 | 5.5%–7% |
| Edmonton | $350,000–$500,000 | $1,200–$1,800 | 5.5%–7% |
| Winnipeg | $300,000–$450,000 | $1,000–$1,500 | 5.5%–7% |
| Halifax | $400,000–$600,000 | $1,400–$1,800 | 5%–6.5% |
Duplex due diligence checklist
- Confirmed zoning permits two legal units
- Verified building permits for both units (if converted)
- Reviewed current leases and rental history
- Confirmed fire separation meets building code
- Checked separate entrances, kitchens, and bathrooms
- Reviewed utility setup (separate meters or shared?)
- Assessed structural condition (roof, foundation, systems)
- Confirmed adequate parking
- Reviewed property tax classification (residential vs multi-res)
- Obtained insurance quote for a duplex (landlord or owner-occupied)
- Calculated cash flow with realistic vacancy (5%) and maintenance (10%) assumptions
- Reviewed local rent control rules (Ontario, BC, PEI, Manitoba)