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A single-unit rental property is straightforward to understand. One tenant, one lease, one rent cheque, one repair call at a time. A duplex or triplex is structurally different — more income streams, more tenants, more compliance obligations, and a different analysis framework before you buy.
London, Ontario has a solid supply of duplex and triplex properties, particularly in neighbourhoods like Old East Village, Old North, Wortley Village, and areas near Fanshawe College. Entry prices are lower than comparable properties in Toronto or Hamilton, and tenant demand — driven by Western University, Fanshawe, and major healthcare employers — keeps vacancy rates below 2%.
This guide walks through everything you need to evaluate a multi-family property in London: cash flow analysis, zoning rules, due diligence, the tenanted-purchase rules, and what changes operationally once you own one.
Duplex, Triplex, or Fourplex: What Changes at Each Level
The differences between a duplex and a fourplex aren't just about unit count. Financing, operations, and compliance all shift.
Duplex (2 units). The most common multi-family entry point. You can finance a duplex with a standard residential mortgage if you live in one unit (owner-occupied). If it's a pure investment purchase, it requires a conventional or commercial mortgage depending on the lender. Complies with standard RTA rules. Each unit needs its own Rental Housing Licence if you're renting both.
Triplex (3 units). Same mortgage treatment as a duplex. Three separate tenancies under the RTA. Three separate Rental Housing Licences required. Three separate lease agreements. Management complexity increases meaningfully — triple the likelihood of a vacancy, triple the potential for a simultaneous maintenance call.
Fourplex (4 units). Four units is the maximum for a residential mortgage in most cases. At 5+ units, you cross into commercial financing. This is a meaningful threshold for investors: the financing cost, amortization, and down payment structure change.
What does NOT change regardless of unit count: Every unit is still governed by the RTA. Every tenancy requires a proper N4 before an L1. Every rent increase still requires 90 days' written notice using the N1. The LTB process — including the 8–14 week hearing timeline and 4–8 week Sheriff enforcement in London — is identical whether you have one unit or four.
Cash Flow Analysis: What the Numbers Look Like in London
Buying on yield rather than appreciation is the only defensible framework for a rental investment. Here's how to run the numbers for London.
Step 1: Establish gross income
Use current market rents, not asking rents, and not the prior owner's rents (which may be below market on older tenancies).
London market rent ranges for 2026 (Prospera leasing data):
| Unit Type | Monthly Rent Range |
|---|---|
| Bachelor / Studio | $1,200–$1,450 |
| 1-Bedroom | $1,500–$1,850 |
| 2-Bedroom | $1,900–$2,250 |
| 3-Bedroom | $2,300–$2,800 |
For a standard London duplex with two 2-bedroom units, realistic gross income is $3,800–$4,500/month ($45,600–$54,000/year). A triplex with three 2-bedrooms reaches $5,700–$6,750/month.
Step 2: Apply expense assumptions
A rough expense ratio for a multi-family property in London is 35–45% of gross rent. That includes property taxes, insurance, maintenance reserves, utilities (if any are landlord-paid), and vacancy allowance.
Common error: investors use the prior owner's reported expenses and miss: the vacancy allowance, capital reserve (roof, windows, furnace), and management costs if they intend to hire a property manager.
| Expense Category | Monthly Estimate (2BR duplex) |
|---|---|
| Property taxes | $350–$500 |
| Insurance (multi-family) | $150–$250 |
| Maintenance / repairs | $200–$400 |
| Capital reserve (1% of value/year) | $375–$500 |
| Vacancy allowance (4–6% of gross) | $150–$225 |
| Management fee (if applicable, 8–10%) | $300–$450 |
| Total expenses | $1,525–$2,325 |
Net operating income (NOI) on a duplex at $4,150/month gross and $1,800/month expenses: $2,350/month ($28,200/year).
Step 3: Calculate gross yield and cap rate
Gross yield = Annual gross rent ÷ Purchase price On a $550,000 duplex at $49,800/year gross: 9.05% gross yield
Cap rate = NOI ÷ Purchase price At $28,200 NOI: 5.1% cap rate
A cap rate between 4.5% and 6% is typical for London multi-family in 2026. Under 4% means the price is stretched. Above 7% warrants scrutiny — usually means deferred maintenance, below-market tenancies, or a building with compliance problems.
For a deeper look at the cash flow math and break-even analysis for London properties, see Rental Property Investing in London, Ontario.
Zoning: What London Permits Before You Buy
Zoning governs what you can legally do with the property. Confirm zoning before making an offer — do not rely on the listing description or the seller's representation.
R1 zones (single-detached). The province's More Homes Built Faster Act now permits up to three residential units as-of-right on lots with municipal water and sewer services — even in R1 zones. This means you can legally add a second and third unit to an existing R1 property, subject to Building Code, Fire Code, and City of London registration requirements. However: lots on private services (well and septic) are excluded from this rule.
R2 and R3 zones. Permit semi-detached and row dwellings, often with existing secondary suites. R3 allows low-density multi-family. These zones are common in Old East Village, the Old North area, and the streets surrounding Western's campus.
R4 and higher. Higher-density residential — apartment buildings and taller multi-unit structures. Not relevant for most duplex/triplex purchases.
Practical step: Before any offer, go to london.ca and look up the property on the interactive zoning map. Then call Planning and Development (519-930-3500) to confirm the current use is permitted and whether any additional units would require a zoning amendment.
For a detailed breakdown of London's zoning framework, see London Ontario Zoning for Rental Properties.
Licensing and Registration: London's Compliance Chain
Every rental unit in London requires a Rental Housing Licence. For a triplex, you need three separate licences — one per unit.
First-year licence cost: $275–$350 per unit, depending on unit size and whether a property standards inspection is required.
Annual renewal: Due in March each year. Renewal is tied to property standards compliance. An open Order to Comply from Property Standards blocks renewal.
Second unit registration: If the property contains a basement apartment or secondary suite, it must be registered with the City as a second unit before applying for the Rental Housing Licence. This is a separate process involving a city inspection and takes 4–8 weeks.
What happens at purchase: The prior owner's licences do not transfer to you. They expire on the existing holder's name. You apply for new licences as the new owner. Build 4–8 weeks into your timeline for initial licence approval — you cannot legally rent units during that period without a valid licence.
St. Thomas and Strathroy: Neither municipality has a rental housing licensing program. Provincial code requirements (Building Code, Fire Code) still apply to second units, but there is no registration or annual licence obligation.
Before you keep reading
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Local market shifts, RTA/LTB changes that actually affect your properties, and real lessons from managing rentals. One short email. No fluff.
For the step-by-step London licensing process, see City of London Rental Unit Licence.
Due Diligence: What to Inspect Before You Close
Multi-family due diligence goes beyond a standard home inspection. You are buying an operating business with income, tenancies, and potential liabilities.
Request and review:
- All current lease agreements (written and verbal)
- Last 12 months of rent payment history
- Any open maintenance requests or outstanding repair items
- Utility bills for common areas and any landlord-paid utilities
- Current Rental Housing Licence status (ask the seller for copies, then verify at london.ca)
- Any open Orders to Comply from Property Standards
- Building permit history (unpermitted work is a compliance liability you inherit)
- Insurance history (prior claims indicate potential issues with the structure)
Building inspection specifics for multi-family:
- Separate electrical panels for each unit (required for individual tenant metering)
- Fire separation between units (especially relevant for basement apartments)
- Smoke and CO alarm installation and condition
- Roof, foundation, and exterior condition — costs scale with a multi-family building
- Heating system: central vs. individual furnaces (individual is preferable operationally)
- Plumbing stack condition for a multi-storey building
Confirm rent amounts and deposit status. Ask for the last month's rent deposit amount for each tenancy. This deposit — with accumulated interest — transfers to you on closing as a credit on the statement of adjustments. Confirm the exact amount with the seller and verify it against the lease. See Buying Property with Existing Tenants in Ontario for a full breakdown of what transfers at closing.
Buying a Tenanted Multi-Family Property
Most duplexes and triplexes for sale in London are occupied. The tenancies do not end at sale. Under the RTA, all existing tenancies transfer to you as the new landlord automatically.
What transfers to you:
- Each lease agreement on its current terms
- The rent amount — you cannot renegotiate on day one
- The last month's rent deposit plus accumulated interest
- Any existing maintenance obligations the prior landlord hadn't fulfilled
- The rent increase history (the 12-month cycle continues — if the prior landlord raised rent three months ago, you cannot raise again for nine months)
N12 own-use notice from the new owner. If you intend to occupy one of the units yourself, you may serve an N12 notice. However, you cannot serve an N12 until you actually own the property. Serving it before closing is invalid. After closing, the N12 requires 60 days' notice and one month's rent in compensation to the tenant. You must genuinely intend to occupy — bad-faith N12 applications carry serious LTB consequences.
Rent control. Units first occupied on or after November 15, 2018, are exempt from rent control. On these units, you can raise rent to any amount on the next increase cycle, with proper 90-day N1 notice. Units first occupied before that date are subject to the annual guideline (2.5% for 2026). For a multi-family property with a mix of older and newer units, you may have both rent-controlled and exempt units in the same building. Track each unit separately. See Ontario Rent Control Exempt Properties for the full rules.
Common Mistakes When Buying Multi-Family in London
1. Buying on gross rent without running expenses. A duplex at $4,000/month sounds good until you add property taxes, insurance, maintenance, and a capital reserve. Do the full cash flow analysis before making any offer.
2. Assuming the building permits everything. Sellers commonly list a property as a "legal duplex" or "legal triplex." Verify this independently through the City of London's building permit records and zoning confirmation. Unpermitted units are a compliance liability you inherit.
3. Missing the licence transfer gap. The prior owner's Rental Housing Licences do not transfer. Expect 4–8 weeks to obtain new licences as the new owner. Factor this into your closing timeline and possession planning.
4. Accepting partial or undocumented rent payment history. If a tenant has a history of late or partial payment, that pattern likely continues. Ask for 12 months of bank statements showing deposits, not just the seller's assurance.
5. Skipping fire separation and egress confirmation. Especially relevant for older buildings with basement suites. Inadequate fire separation or non-compliant egress windows are expensive to fix and may trigger a Property Standards order if the City inspects.
6. Not factoring management complexity. A triplex with three simultaneous L1 proceedings, three rent increase cycles, and three vacancies in a single year is manageable — but it requires systems. Self-managing a multi-unit property without those systems is where landlords run into trouble.
7. Underestimating the capital reserve. Older London multi-family buildings (1940s–1970s construction common in Old East Village and Old North) may have aging roofs, knob-and-tube wiring, cast-iron plumbing, and single-pane windows. A 1% annual capital reserve on purchase price is a minimum — older buildings warrant 1.5–2%.
Managing a Duplex or Triplex
Multi-family management follows the same RTA rules as a single unit. But the volume is higher, and mistakes compound across tenancies.
Records. Keep separate records for each unit: lease, rent payment history, maintenance log, deposit amount and interest calculations, rent increase history. A single missed rent increase interest payment across three units becomes three T1 applications. See Landlord Record Keeping in Ontario for a recordkeeping system that scales.
Rent increases. Each unit has its own 12-month cycle. On a triplex, you may be sending N1 notices at different times throughout the year. Set calendar reminders for each unit's eligible increase date.
Maintenance. Common areas — shared entrances, parking, exterior — are your responsibility regardless of which tenant benefits. Shared utilities (common area lighting, landscaping) need to be factored into your operating budget.
Insurance. A standard homeowner policy does not cover a rental property. A multi-family landlord policy covers the structure, loss of rental income during repairs, and your liability. Get a policy specific to the building configuration — duplex/triplex rates differ from single-unit investment property rates.
FAQ
How much does a duplex cost in London, Ontario in 2026? A typical London duplex sells for $450,000–$650,000 depending on location, condition, and unit configuration. Old East Village and areas near Western tend to be at the higher end. South London and areas near Fanshawe are often more accessible. Triplexes typically range from $550,000 to $750,000.
Can I live in one unit and rent the other on a standard mortgage? Yes. Owner-occupied duplexes qualify for standard residential mortgages, including high-ratio (under 20% down) financing if the owner occupies one unit. Investment-only multi-family generally requires 20% down minimum and may require a commercial product at 4+ units. Confirm with your lender before making an offer.
Do I need a separate Rental Housing Licence for each unit? Yes. The City of London requires a separate licence for each rental unit. A triplex requires three licences. Licences are tied to the unit, not the building address. Fees are $275–$350 per unit for initial licensing.
What if one of the units is a basement apartment? If a basement suite is present, it must be registered with the City of London as a second unit before you can apply for a Rental Housing Licence for that unit. Second unit registration involves a city inspection and takes 4–8 weeks. See Basement Apartment Landlord Guide for Ontario for the full compliance sequence.
What happens to existing tenants when I buy the property? All tenancies transfer to you automatically. You become the landlord under the existing lease terms. You cannot raise rents immediately, change lease terms, or evict tenants simply because you are the new owner. See Buying Property with Existing Tenants in Ontario for a full breakdown.
Can I increase rents above the guideline on a duplex I just bought? Only if the units are rent-control exempt (first occupied on or after November 15, 2018). On exempt units, you may raise rent to any amount with proper 90-day N1 notice and at least 12 months since the last increase. On rent-controlled units, the 2.5% guideline applies regardless of ownership change.
What LTB timeline should I plan for if a tenant stops paying rent? In London/Middlesex, an L1 (eviction for non-payment) currently takes 8–14 weeks from filing to hearing, plus 4–8 weeks for Sheriff enforcement after the void period. The full timeline from first missed rent to vacant possession is typically 4–6 months. This is a material cash flow consideration when modeling a multi-unit purchase.
Should I manage a duplex myself or hire a property manager? One duplex with stable, long-term tenants is manageable for most landlords. At two or more properties — or any multi-unit building with active vacancies, compliance obligations, or a maintenance backlog — professional management often pays for itself in avoided LTB errors, faster vacancy fill times, and system discipline. See Property Manager vs. Self-Managing in Ontario for the break-even math.
A Note on Prospera
Prospera Properties manages duplexes, triplexes, and fourplexes for small landlords across London, St. Thomas, and Strathroy. If you are buying a multi-family property and want to understand what full-service management would cost and what it covers, visit our pricing page or take the Freedom Score assessment to see whether management makes sense for your situation.