// property types

Duplexes, triplexes and fourplexes in London

Last reviewed October 30, 2026

Small multi-unit buildings, from two to four units, sit in a sweet spot for investors. They're still financed as residential properties, they spread vacancy risk across several units, and you can live in one of them. In London, most are older conversions or purpose-built buildings in established neighbourhoods.

Where you'll find them

London's small multi-units tend to cluster in older parts of the city, including neighbourhoods around downtown, Old East Village, SoHo, Wortley Village and the areas near Western University. Many are large older houses converted into two or three units decades ago. Purpose-built duplexes and fourplexes also appear in mid-century neighbourhoods. With recent provincial and City changes encouraging "gentle density", new small multi-unit projects are becoming more common too.

Legal status matters most

The single most important question with any multi-unit is: is each unit legal? A "triplex" in a listing could be a properly permitted three-unit building, or a duplex with an unpermitted third unit. That affects:

• Whether the units can be licensed for rental
• Fire safety and liability
• Insurance coverage
• Financing, since lenders may only count legal units
• Resale value

Ask for building permits, zoning confirmation and any Fire Code inspection records. Your lawyer can make the offer conditional on satisfactory confirmation of the legal number of units, and can request zoning compliance information from the City.

Financing 2–4 unit properties

Mortgage insurers and lenders set the exact criteria, including how much rental income they'll count, so speak to a lender or broker who regularly finances multi-unit residential properties. Five units and up is generally commercial financing, with different rules entirely. See financing.

Due diligence checklist

• Rent roll: current rents, lease start dates and terms for each unit. Ask whether any tenants are on month-to-month leases.
• Leases and estoppel information: confirm what the tenants believe their rent, deposit and terms are, ideally in writing.
• Rent control status: units first occupied before November 15, 2018 are generally subject to the guideline, so below-market rents can't be raised quickly.
• Utilities: who pays what? Separately metered hydro, shared water and a shared furnace all affect your costs.
• Inspection: roof, electrical (watch for older wiring), plumbing, fire separations, smoke and CO alarms, and egress from every unit.
• Licensing: is the property currently licensed with the City, and can it be?
• Insurance quote: landlord or multi-unit coverage, obtained during your conditional period.

Running costs to budget

• Property tax (multi-residential tax class applies only to larger buildings; small ones are usually taxed as residential)
• Insurance (landlord or multi-unit policy)
• Utilities you pay as the owner
• Maintenance and capital reserves. Older buildings need more.
• City licensing fees
• Property management, if you don't self-manage (often a percentage of rent)
• Vacancy and turnover costs

Value-add opportunities

Some investors look for multi-units with untapped potential: adding a legal unit where zoning allows, separating utilities, upgrading tired units as they turn over, or improving energy efficiency. Each takes capital and permits, and works only where the numbers support it.