Hamza Nouman
REALTOR® · Investment Property Specialist · Cityscape Real Estate Ltd.
Every so often an investor emails me a screenshot of one of my own deal scores with a single line: "there's no way."
Usually it's a big-bedroom detached in Malton. Seven bedrooms, three baths, high six figures, and a cash flow number that looks impossible. Their instinct is that the model is renting bedrooms individually like a rooming house and calling it income.
That instinct is healthy. It's also, in this case, wrong — and the reason it's wrong is worth more to you than the deal itself.
Where the number actually comes from
Take a real example shape: a seven-bedroom detached in Malton around $769,000, scoring about 6.9% on cap rate.
The model does not price seven bedrooms at seven rents. It does this instead:
| Component | Assumption | Monthly |
|---|---|---|
| Main unit (4 bed) | Malton 4-bed rent + detached premium | ~$3,900 |
| Legal basement (3 bed) | 3-bed self-contained suite | ~$2,000 |
| Total | ~$5,900 |
Two units. Not seven rooms. A four-bedroom main floor and a three-bedroom basement apartment — which, if you have spent any time in Malton, Malton Woods, or the pockets around Goreway and Morning Star, you know is not exotic. It is close to the default configuration.
The bedroom count on the listing is the sum of both units. That is what makes it look alarming at a glance. A seven-bedroom house sounds like a boarding operation. A 4+3 duplex-style detached sounds like half the street.
Why the distinction matters enormously
Rooming-house math and two-unit math are not the same business, and they don't carry the same risk:
Rooming houses need per-room leases, licensing in most municipalities, far more intense management, and they collapse to a fraction of projected income the moment occupancy dips. Seven rooms at $800 sounds like $5,600 until three rooms sit empty in February.
A legal two-unit property is two leases. Vacancy risk is chunky but rare. Financing treats it normally. Insurance treats it normally. The City treats it normally — if the second unit is legal.
That last clause is the entire deal.
The question that actually decides it
Not "is the rent realistic?" — you can verify that in an afternoon on Facebook Marketplace and rentals.ca. The question is:
Is the basement unit legal, or is it "potential"?
The model distinguishes these. A registered second unit gets full credit. A basement that could become one gets discounted to about 85% of the same figure, because you are underwriting a renovation and an approval you do not yet have.
For a property to have a legal second unit in Mississauga it generally needs to satisfy the Second Unit registration requirements — separate entrance, fire separation, egress windows, ceiling height, parking. Retrofitting a non-conforming basement to that standard is routinely $40,000 to $80,000, and sometimes the ceiling height alone makes it impossible at any price.
So when a listing says "in-law suite" or "separate entrance," what you are reading might be:
- a registered second unit (income is real today),
- a functional-but-unregistered apartment (income is real but uninsurable and unfinanceable as income, and the City can order it closed), or
- a rec room with a side door (income is a renovation project).
Three completely different investments wearing the same listing description.
How to check in about twenty minutes
- Ask the listing agent directly, in writing: "Is the second unit registered with the City of Mississauga as a Second Unit?" A yes should come with paperwork.
- Look at the photos properly. A legal suite has a real kitchen, a separate entrance that doesn't route through the main living space, and full-size egress windows in the bedrooms. Low ceilings and tiny windows are a hard stop.
- Price the retrofit before you offer, not after. If the answer is "potential," the number you should be underwriting is 85% of that suite income minus the cost and time to get there.
- Verify the main-unit rent independently. Search current Malton listings for a comparable 4-bedroom main floor. If they are asking $3,600 and my model says $3,900, adjust it down — the model is a starting point, not a comp.
The honest limitations
I would rather you know these than discover them:
- Rent estimates are neighbourhood-level, not property-level. They cannot see that a kitchen is from 1988 or that the yard backs onto Highway 427.
- The suite income assumes the suite is rentable now. For "potential" it is discounted, but discounting is not the same as pricing your specific renovation.
- Cash flow assumes a mortgage rate around 4.9% on a five-year fixed — a realistic discounted contract rate, not the Bank of Canada posted rate. If your broker gets you something different, every number moves.
- Property tax is estimated from the purchase price. The actual bill can differ.
So — real or fantasy?
Real, with conditions attached. The rent is two units, not seven rooms. The math holds if the second unit is legal and the main-floor rent survives contact with actual comps.
What makes a deal score useful is not that it is right. It is that it tells you which single question to go answer. For big-bedroom Malton detached, that question is always the same: is the basement registered?
Everything else is arithmetic.
What this means for investors
- A high bedroom count is a signal to check the unit structure, not a red flag by itself.
- Legal beats potential by more than the price difference usually reflects.
- Underwrite "potential" suites at the discounted income and subtract your retrofit estimate — do not do only one.
- Verify the main-unit rent against live comps before you write an offer; that single number moves cap rate more than anything else on the page.
Every listing on MississaugaInvestor.ca now shows the assumed rent and its breakdown directly on the card, so you can audit the assumption before you trust the score. Browse the current listings or run your own numbers in the mortgage calculator.
Based on June 2026 TRREB Market Watch data. Educational commentary from a licensed sales representative — not financial advice. Verify unit legality with the City of Mississauga and your own professionals before purchasing.
Need help with this topic?
Book a free 15-minute investor call with Hamza. No obligation — we'll walk through your numbers together.
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