Case Study  ·  First Time Buyers & Investors  ·  August 2026  ·  6 minute read

House Hacking a Duplex:
A Tenant Pays Part of Your Mortgage

CMHC now insures owner occupied properties of up to four units with as little as 5% down, a rule that used to demand 20%. That single change makes a $1,000,000 duplex reachable with less cash than a $1,000,000 house.

$75,000
Minimum down payment on a $1,000,000 legal duplex, which is 7.5%
$115,010
Total cash to close, versus $236,850 for a regular house
$797
Lower net monthly cost than buying a $1,000,000 house instead
The short version
  • You put down $121,840 less cash than on a comparable single family home, because CMHC now treats an owner occupied duplex like a regular house purchase.
  • You pay $797 a month less to live there, roughly $9,564 a year, even though you carry a much bigger mortgage. A tenant covers a third of the building.
  • A duplex often buys you more house. With rental income helping you qualify, the duplex you can afford is frequently larger than the single family home you can afford.
  • You pay for it in work, not dollars. Screening tenants, repairs, bookkeeping, and Ontario's landlord rules. This is a small business you live inside.
  • The deal breaker is legality. If the second unit is not a legal one, walk. No insurance, no financing, and a possible order to remove it.
🔑 The Rule That Changed Everything

Five percent down on a two unit building

For decades, anything with more than one unit meant 20% down. CMHC now treats an owner occupied one to four unit property much like a regular home purchase.

01

You must live there

Owner occupancy is the condition for the whole thing. You live in one unit, you rent the other.

02

Tiered down payment

For one or two units, 5% on the first $500,000 and 10% above it. Three or four units requires 10% of the whole price.

03

$1.5M price ceiling

CMHC will not insure above $1.5 million. Over that, you are back to 20% down and conventional financing.

04

Rent helps you qualify

Lenders can add up to 50% of the projected rent from units you do not occupy to your qualifying income.

That fourth point is the quiet one. The down payment change gets the headlines, but the rental income offset is often what actually gets a buyer approved, and it is why a duplex buyer can frequently afford a bigger, better located property than they could as a single family buyer.
🏢 The Deal

A $1,000,000 legal duplex, run end to end

Our buyer purchases a legal two unit house in the east end, occupies the larger unit, and rents the second for $2,000 a month.

🏦

The financing

CMHC insured, owner occupied two units
Purchase price$1,000,000
Down payment (5% + 10%)$75,000
Base mortgage$925,000
Loan to value92.5%
CMHC premium at 4.00%$37,000
Total mortgage$962,000
💵

Cash to close

What you actually need in the bank
Down payment$75,000
Ontario land transfer tax$16,475
Toronto municipal land transfer tax$16,475
Ontario PST on CMHC premium$2,960
Legal, title, duplex inspection$4,100
Cash required$115,010
Two line items catch people out. The $37,000 CMHC premium is added to your mortgage, so you finance it. But the 8% Ontario sales tax on that premium, $2,960, must be paid in cash at closing. And first time buyer land transfer tax rebates apply only to the portion you occupy on a duplex, so budget conservatively and confirm with your lawyer.

💰 Cash needed to close

$1,000,000 duplex at the CMHC minimum versus a $1,000,000 house at 20% down
Duplex, 7.5% down House, 20% down CMHC insured Conventional $115,010 $236,850 The duplex needs $121,840 less cash, and comes with a tenant.
Both properties cost the same and attract identical land transfer tax. The entire difference is the down payment rule.
📅 The Monthly

What it costs to actually live there

📋

Monthly running costs

$962,000 mortgage at 4.04% over 30 years
Mortgage principal and interest$4,615
Property tax$475
Insurance (duplex, landlord)$250
Water and common utilities$150
Maintenance reserve upkeep through the year: furnace and roof repairs, plumbing, appliances, painting between tenants$350
Vacancy allowance at 4%$80
Total monthly outlay$5,920
🏷

What the tenant covers

Second unit rented at $2,000
Total monthly outlay$5,920
Less rent received− $2,000
Your net housing cost$3,920
Same price house, no tenant, 20% down$4,717
Monthly advantage$797 better
If you take the smaller unit instead$3,120

📈 Where the money goes each month

Duplex with a tenant versus a comparable house without one
$0$2,000 $4,000$6,000 $2,000 rent $3,920 you $4,717 you $5,920 total $4,717 total Duplex with tenant House, no tenant $75,000 down $200,000 down
Covered by your tenant Paid by you, duplex Paid by you, house
The duplex owner carries a bigger mortgage and still pays less each month. They put down $125,000 less, financed a $37,000 insurance premium, and are still $797 a month better off, because a tenant covers roughly a third of the building's costs.
$9,564
Annual advantage over the comparable house, at $797 a month.
$24,000
Gross rent collected per year from a single $2,000 unit.
$3,120
Net monthly cost if you live in the smaller unit and rent the larger at $2,800.
Worth sitting with for a second. Because rental income helps you qualify and the down payment requirement is lower, the duplex you can buy is often physically larger and better located than the single family home you could afford instead. A bigger duplex at $1.1 million can be the better long term asset than a smaller freehold at the same price with several hundred fewer square feet and no income. We are working on a full case study comparing those two directly.
⚠️ The Fine Print

Six things that can go wrong

"Legal duplex" is a legal question

A basement with a kitchen is not a legal second unit. You need proper zoning, permits, fire separation and egress. Buying an illegal unit can mean an order to remove it, no insurance, and no financing. Verify before you offer.

You are a landlord under the RTA

Ontario's Residential Tenancies Act governs everything, including rent increase limits and a Landlord and Tenant Board process that can take many months. A bad tenant costs far more than a vacant unit.

The CMHC premium is real money

$37,000 added to the mortgage costs you interest for as long as you carry it. A low down payment buys access, not a discount.

Rental income is taxable

You declare the rent and deduct a proportional share of interest, taxes, insurance and maintenance. Not free money, and it needs proper bookkeeping from day one.

Principal residence exemption

Renting part of your home can affect the capital gains exemption on the rented portion, particularly if you claim depreciation. Speak to an accountant before closing.

Maintenance doubles

Two kitchens, two bathrooms, two sets of appliances, two tenants' worth of wear. The $350 reserve is a starting point. Older east end stock can consume more.

One more that catches new landlords. If you ever want the tenant's unit for yourself or family, Ontario has a specific process with compensation requirements and penalties for bad faith. Do not assume you can simply reclaim the second unit whenever you like.

The honest bottom line

House hacking is the most effective affordability tool available to a Toronto buyer right now, and it is also a small business you live inside. The $121,840 you save in cash to close and the $797 you save every month are real, but they are earned through landlord work, higher maintenance and more risk than owning a single family home. Priced honestly, it is a very good trade for the right person and a poor one for everyone else.

The strongest case

A first time buyer with steady income and about $120,000 saved who would otherwise be priced into a condo. A duplex buys them a house, a tenant, and a foothold in the freehold market at once.

The weakest case

A buyer scraping together exactly the $75,000 minimum with nothing behind it. One vacancy, one furnace, or one Landlord and Tenant Board hearing and the whole structure is under strain.

How we actually help with this

We verify legal unit status before you offer, because that single question decides whether the deal exists at all. We check zoning, permits, fire separation and retrofit compliance, connect you with a lender who actually writes CMHC insured multi unit deals rather than one who says it cannot be done, and give you realistic rents for the specific unit rather than a citywide average. We will also tell you when a duplex is the wrong answer for you.

Figures are illustrative and for education only. The model assumes a $1,000,000 legal two unit owner occupied property in Toronto, a CMHC minimum down payment of 5% on the first $500,000 plus 10% on the balance ($75,000, or 7.5%), a 4.00% CMHC premium on a 92.5% loan to value ratio ($37,000, added to the mortgage), 8% Ontario PST on that premium payable in cash at closing ($2,960), and a $962,000 mortgage at 4.04% over a 30 year amortization ($4,615 per month). Thirty year insured amortizations are available to first time buyers and buyers of new builds; other buyers should model 25 years, which raises the payment to approximately $5,099 and removes most of the monthly advantage shown here. Land transfer tax is calculated on Ontario's residential schedule plus Toronto's municipal land transfer tax, with no first time buyer rebate applied; rebates of up to $4,000 provincially and $4,475 municipally may apply to the owner occupied portion and should be confirmed with your lawyer. Property tax, insurance, utilities, maintenance and vacancy are estimates and vary substantially by property and by ward. The comparison property is a $1,000,000 single family home with 20% down and an $800,000 mortgage at 3.94% over 30 years. Mortgage rates reflect nationally advertised rates as of early August 2026 and are not an offer of credit. Rental figures reflect east end Toronto two unit properties and should be verified for any specific address. This is not financial, mortgage, tax or legal advice. Speak with a licensed mortgage professional, an accountant, a real estate lawyer, and Mo Realty before proceeding. Sources: CMHC mortgage loan insurance rules for owner occupied one to four unit properties, 2026; Ontario Ministry of Finance land transfer tax rates; City of Toronto municipal land transfer tax schedule; Ontario Residential Tenancies Act; Ratehub.ca and WOWA.ca mortgage rate data, August 2026; Rentals.ca and Zumper Toronto rent data, 2026; TRREB Market Watch, July 2026.
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Want to see if house hacking works for you?

Tell us your savings, your income and where you want to live. We will show you what you qualify for with the rental offset included, and we will verify the legal unit status on anything you are serious about before you write an offer.

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