Detached homes made up just 18% of new housing starts in Ontario as of 2025, down from roughly 50–60% two decades ago. That shift is reshaping what Canadian families can actually buy. With land running out in cities like Toronto, Mississauga, and Vaughan, and government policy pushing density, the traditional single-family home is no longer the default option for most buyers. Instead, duplexes — part of what planners call “missing middle” housing — are becoming the practical choice for families who want more space than a condo but can’t afford a detached house.
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This article is general information only and does not constitute professional advice. For your specific situation, consult a qualified professional.
Duplexes sit in a sweet spot. They offer ground-oriented living with a yard, more square footage than a condo, and often the option to rent out one unit to offset the mortgage. The Ontario government now backs easier zoning approvals for missing middle housing through programs like the Housing Accelerator Fund, and incentives for purpose-built rental and new construction favour multi-unit homes over luxury detached builds. For families who would have bought a detached house a generation ago, a duplex is increasingly the realistic alternative. Here’s what you actually need to know.
The term you’ll hear a lot in this conversation is missing middle.
What I tend to notice is that families who assume only a detached house will work often overlook what a well-located duplex can offer. The space difference is smaller than you’d think, and the financial difference is larger than most expect. The path to ownership now runs through missing middle housing, not around it.
What a Duplex Actually Costs Compared to a Detached Home
Buying a duplex isn’t just about the purchase price. The full cost picture includes the mortgage, property taxes, utilities, maintenance, and — if you rent out part of the property — the income that offsets those expenses. The table below shows how a typical duplex compares to a detached home and a condo across the factors that matter most to families.
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| Factor | Detached Home | Duplex | Condo Apartment |
|---|---|---|---|
| Typical price range | Highest | Moderate | Lowest |
| Land / yard space | Largest | Moderate | None or minimal |
| Rental income potential | Limited (basement suite if allowed) | Built-in (second unit) | Not allowed in most buildings |
| Government incentives | Lower (luxury detached not prioritised) | Higher (missing middle priority) | Moderate |
| Monthly carrying cost | Highest | Reduced by rental income | Lowest but no rental offset |
| Zoning approval ease | Restricted in many areas | Easier under new policies | Dedicated zones |
The key difference is the rental income. A duplex in a city like Toronto or Mississauga might cost more than a condo upfront, but the second unit can bring in $1,500–$2,500 per month depending on location and size. That changes the real monthly cost dramatically. A detached home at the same price offers no such offset unless it has a legal basement apartment — and many older detached homes don’t.
Land is the other hidden factor. Detached homes require more land per unit, and land is scarce in Ontario’s major cities. The Ontario government now promotes density through transit-oriented housing and multi-unit developments, which means duplexes get faster approvals and better policy support than new detached builds. If you’re comparing a duplex and a detached home in the same neighbourhood, the duplex will almost always sit on a smaller lot — but the trade-off is a lower purchase price and a rental income stream.
Where Families Get Tripped Up on Duplexes
Waiting for detached prices to drop
A lot of families hold out for a detached home, assuming the market will correct. But the data points the other way. Detached homes made up only 18% of new Ontario housing starts in 2025, and that share could drop to 10–12% within 20 years. Supply is shrinking, not growing. Waiting for detached prices to fall while the supply of new detached homes dries up is a risky bet. Meanwhile, duplexes are being built faster, with better government support, and at prices that are more achievable for families. The longer you wait, the more the gap between a duplex and a detached home widens — not in your favour.
Underestimating the rental income effect
Many first-time duplex buyers treat the rental unit as a bonus rather than a core part of the financial plan. That’s a mistake. The rental income from a second unit changes the affordability calculation completely. A $700,000 duplex with a $2,000 monthly rental income effectively costs the same to carry as a $500,000 home with no rental income, depending on interest rates and down payment. The research shows that missing middle housing is designed to help families offset mortgage costs through rental suites. If you don’t factor that in, you’ll overestimate what you can afford and miss out on viable duplex options.
Not checking zoning and legal requirements early
Not every duplex is set up for a legal rental from day one. Some older duplexes have units that don’t meet current fire separation, parking, or entrance requirements. Buyers who assume the rental is ready to go can face costly upgrades or delays. Before making an offer, check whether both units have separate entrances, proper fire-rated separation, and compliance with local zoning bylaws. The Ontario government’s push for easier approvals applies to new builds and conversions, but existing duplexes may still have grandfather clauses or restrictions. A quick call to the municipal building department or a real estate lawyer can save you thousands in unexpected work.
How to Buy a Duplex in Today’s Market
Financing a duplex purchase
Lenders treat duplexes differently than single-family homes. If you plan to live in one unit and rent the other, the rental income from the second unit can be included in your mortgage application. Most lenders will count 50–80% of the projected rental income toward your qualifying income, depending on the lender and the lease agreement. You’ll need a lease or a market rent assessment from a real estate agent. The down payment for a duplex is the same as for a detached home — 5% for the first $500,000 and 10% on the portion above that, up to $999,999 — but the rental income can make it easier to qualify for a larger mortgage. If you’re buying a duplex as a pure investment (not living in it), the down payment jumps to 20%.
Zoning, permits, and legal structure
Before you buy, confirm that the duplex is legally zoned for two units. Some properties are listed as duplexes but only have one legal unit, with the second unit being an unpermitted conversion. That can cause problems with financing, insurance, and resale. The Ontario government’s missing middle policies make it easier to get permits for new duplex builds and conversions, but existing properties vary. Ask for a copy of the occupancy permit and check the municipal zoning map. If the property needs a variance or rezoning, factor in 6–12 months of additional time and costs. A legal professional can help you navigate the due diligence process here.
Managing the rental unit from day one
If you’re buying a duplex to live in one unit and rent the other, you’re becoming a landlord immediately. That means understanding tenant rights, lease agreements, and the Residential Tenancies Act in your province. Ontario’s rules around rent increases, eviction, and maintenance are strict. Set up a separate bank account for rental income and expenses, get landlord insurance, and install separate utility meters if possible. A security system for the shared entrance and common areas can also help with safety and liability. The rental income is the main advantage of a duplex, but it comes with responsibilities that a detached homeowner doesn’t face.
Future-proofing: green upgrades and policy shifts
Government incentives for energy-efficient homes and green retrofits are growing. Duplex owners can qualify for rebates on insulation, heat pumps, solar panels, and windows — upgrades that lower utility costs and increase property value. The federal government’s push toward net-zero homes means that older duplexes will eventually need upgrades to meet new standards. If you’re buying a duplex, look for one with good energy performance or budget for improvements. The incentives available now can offset a significant portion of the cost, and the long-term savings on utilities make the numbers work even better. The shift in government policy is clear: luxury detached homes are out, and sustainable missing middle housing is in.
Frequently Asked Questions About Duplexes
Is a duplex cheaper than a detached home in the same neighbourhood? ▾
Can I get a mortgage for a duplex the same way as a detached home? ▾
What happens if I can’t find a tenant for the second unit? ▾
Are duplexes harder to resell than detached homes? ▾
Do I need a special type of insurance for a duplex? ▾
The Shift Away from Detached Homes Is Only Accelerating
The numbers don’t suggest a return to the 2005 housing mix. Detached homes are at 18% of new builds and heading lower. Government policy, land scarcity, and affordability pressures all point in the same direction: missing middle housing like duplexes is the future for Canadian families. The families who adapt earliest — who look at a duplex as a home and an income property combined — will have the most options. Those who hold out for a detached house may find the market has moved on without them.
Remember: this article is general information only. For advice on your specific situation, speak to a qualified professional.
If this was useful, you might also want to read Why More Canadians Are Turning to Tiny Homes and Alternative Living Spaces.
Sources and Further Reading
Why Some Canadians Are Choosing Fractional Home Ownership Instead of Traditional Buying — A look at another alternative path to homeownership when traditional detached homes are out of reach.
The Pros and Cons of Buying Pre-Construction Homes in Canada — Understand the trade-offs of buying new builds, including duplexes and townhomes, before they’re completed.
Garry Sidhu (2025). Government Housing Incentives Canada Ontario 2026. 🔗
Garry Sidhu (2025). House Types Ontario 2026 — Condo, Townhouse, Detached Trends. 🔗
