Plex · Returns · Longueuil · 2026
The honest answer takes three calculations, and it depends on who lives in one of the units: cap rate, cash flow financed at 80%, net cost for the owner-occupant, in Longueuil, at the 2026 median price and the median rent. Labelled assumptions, nothing guessed.
No for the duplex and the triplex, yes for the fourplex: in Longueuil, at the January to September 2026 median price and the median rent of $1,768 per unit, financed at 80%, the duplex ($696,250) loses about $639 a month, the triplex ($900,000) loses about $92 a month, the fourplex ($1,022,503) clears about $941 a month, before tax, with principal repayment included in the debt. Cap rates run from 4.1% (duplex) to 6.3% (fourplex), on either side of the 4.24% mortgage rate. As an owner-occupant, living in one unit of the triplex costs $2,348 a month net, against a rent of $1,768 and a payment of $2,606 on the median house ($602,000, 20% down). Labelled assumptions, reproducible math. Source: Centris (Matrix) and the site's rent pages, team assumptions, compiled October 13, 2026.
The assumptions, before the numbers
A profitability calculation is only worth its assumptions, so here they all are. Prices: the Longueuil medians for January to September 2026 (Centris, Matrix, Income property category): duplex $696,250 (108 sales), triplex $900,000 (143 sales), fourplex $1,022,503 (21 sales). Rent: $1,768 per unit per month, the median of Longueuil's 3 rent pages (leases signed through a broker, past twelve months), from $1,700 to $1,800 depending on the area; it is the median rent of Greenfield Park (median rent in Greenfield Park). Operating expenses: 2% of the price per year (municipal and school taxes, insurance, routine maintenance), a rule of thumb to check building by building. Financing: 80% of the price at 4.24% over 25 years, the same assumptions as our page is an income property profitable in Montreal. No vacancy, no bad debt, no major work: the math is therefore optimistic.
The math, building by building
| At the 2026 median price, financed at 80% | Duplex | Triplex | Fourplex |
|---|---|---|---|
| Median price (sales) | $696,250 (108) | $900,000 (143) | $1,022,503 (21) |
| Price per unit | $348,125 | $300,000 | $255,626 |
| Gross rents per year ($1,768 per unit) | $42,432 | $63,648 | $84,864 |
| Operating expenses (2% of price) | $13,925 | $18,000 | $20,450 |
| Net operating income | $28,507 | $45,648 | $64,414 |
| Cap rate | 4.1% | 5.1% | 6.3% |
| Gross rent multiplier | 16.4 | 14.1 | 12.0 |
| Debt service (80% loan, 4.24%, 25 years) | $36,172 | $46,758 | $53,122 |
| Cash flow per year, before tax | −$7,665 | −$1,110 | +$11,292 |
| Cash flow per month | −$639 | −$92 | +$941 |
| Rent per unit that brings cash flow to zero | $2,087 | $1,799 | $1,533 |
| Purchase price that brings cash flow to zero | $590,000 (−15% vs median) | $885,000 (−2% vs median) | $1,179,000 (+15% vs median) |
The answer to the question in the title, for an investor who does not live there: no for the duplex and the triplex, yes for the fourplex. The cap rate of the duplex is below the 4.24% mortgage rate: each borrowed dollar costs more than it earns. The fourplex clears the most (+$941 a month) because a unit there costs $255,626 against $348,125 for the duplex; its margin disappears with a unit empty for a few months or a roof to redo.
What cash flow does not show
Cash flow is not return. In the first year, the principal repayment built into the payments is about $16,549 on the triplex and $18,802 on the fourplex: money that leaves your account but stays on your balance sheet. Then appreciation: the median triplex in Longueuil gained 121% in ten years ($406,900 in 2016), 8.3% a year compounded; at that pace, the $900,000 triplex would gain about $74,700 in the first year. Past performance does not guarantee the future, and the Longueuil triplex fell in 2023 when rates or supply moved. But that is where a plex earns its return in 2026: principal and appreciation, not just the monthly cheque.
The version that works: the owner-occupant
| You live in one unit, the others are rented | Duplex (5% down) | Triplex (10% down) | Fourplex (10% down) |
|---|---|---|---|
| Rents received per year | $21,216 | $42,432 | $63,648 |
| Debt service (insured loan, 4.24%, 25 years, CMHC premium not counted) | $42,955 | $52,603 | $59,762 |
| Net cost of your unit per month (debt + expenses − rents) | $2,972 | $2,348 | $1,380 |
| For comparison: median rent of a unit | $1,768 | $1,768 | $1,768 |
| For comparison: payment on the median house ($602,000, 20% down) | $2,606 | $2,606 | $2,606 |
Read this way, owner-occupied, the triplex and the fourplex cost their owner less than the median house in Longueuil ($2,606 a month with 20% down), and the fourplex even costs less than a $1,768 rent: the tenants pay for the owner's unit, and part of the owner's principal. The best of the three for housing yourself is the fourplex ($1,380 a month net). The mortgage insurance premium (CMHC or equivalent) is added to the loan and raises these payments by a few hundred dollars a month: to be priced with your mortgage broker.
Longueuil among the 19 cities
- Longueuil ranks 15th of 19 cities on the triplex cap rate (5.1%, median of the cities 6.2%); the most profitable is Saguenay (16.1%), the least Mirabel (4.6%).
- At the median price and the median rent, financed at 80%, the triplex is cash-flow positive in 14 of 19 cities, the fourplex in 16 of 16, the duplex in 10 of 19; in Longueuil, the fourplex is.
- Median monthly cash flow across the cities: duplex +$42, triplex +$603, fourplex +$2,020; in Longueuil, duplex −$639, triplex −$92, fourplex +$941.
- As an owner-occupant, the triplex costs less than the median rent in 13 of 19 cities and less than the payment on the median house in 18; in Longueuil, $2,348 a month against $1,768 in rent and $2,606 for the house.
The three levers that change the answer
- The leases in place. The median rent of signed leases is the rent of units that just turned over; the leases in place in a plex are often lower. A triplex whose units rent 15% below the median ($1,503 instead of $1,768) brings in $9,540 less per year; in Quebec, those rents rise slowly, at the rates set by the Tribunal administratif du logement, and only at renewal. You buy the leases, not the median.
- The purchase price. The Longueuil triplex breaks even on cash flow at $885,000, 2% below the median: the room to negotiate exists, and an offer backed by comparable sales changes the cap rate more than any renovation. Prices by type are in duplex, triplex and fourplex prices in Longueuil.
- The condition of the building. The 2% in expenses assumes a sound building. A roof, brickwork or an electrical entrance to redo runs into tens of thousands of dollars, and an inspector sees them before the offer.
How to read these numbers
The median rent of broker-signed leases in Longueuil ($1,768) is applied to every unit, which overstates buildings with old leases and understates renovated units; the 2% in expenses is a rule of thumb, and a building where the owner pays the heat can exceed 3%. Prices are sale medians (143 triplexes in Longueuil from January to September 2026), not appraisals. The math is deliberately simple so it can be redone on any building: price, leases, taxes, insurance, debt.
Frequently asked questions
Is a plex profitable in Longueuil in 2026?
No for the duplex and the triplex, yes for the fourplex, at the 2026 median price, the median rent of $1,768 and 80% financing: duplex −$639 a month, triplex −$92 a month, fourplex +$941 a month. On total return, with principal repayment ($16,549 in the first year on the triplex) and a historical appreciation of 8.3% a year, the answer changes; as housing, for an owner-occupant, the triplex costs $2,348 a month net.
What cap rate in Longueuil in 2026?
Between 4.1% (duplex) and 6.3% (fourplex) at the median price and the median rent of $1,768, with 2% in expenses; on either side of the 4.24% mortgage rate. A specific building is calculated on its actual leases and taxes; the median of the 19 cities tracked is 6.2% for the triplex.
Is a triplex or a fourplex better in Longueuil?
At the median price, the fourplex ($1,022,503, $255,626 per unit) clears +$941 a month against −$92 for the triplex ($300,000 per unit); it takes $122,503 more, with 10% down if you live in it, 20% otherwise. Across the 19 cities tracked, the fourplex is the most profitable type in 14, the triplex in 5.
What does a plex cost in Longueuil if I live in it?
With 5% down on a duplex and 10% on a triplex or fourplex (insured loan, premium not counted), your unit costs $2,972 a month in a duplex, $2,348 a month in a triplex, $1,380 a month in a fourplex, expenses included and rents deducted, against a median rent of $1,768 and a payment of $2,606 on the median house in Longueuil. The down payment runs from $34,812 to $102,250.
Source: Centris (Matrix) median prices of duplexes, triplexes and fourplexes sold in Longueuil from January to September 2026, Income property category; median rent of leases signed through a broker, twelve months, as published on our rent pages; assumptions on expenses (2%), rate (4.24%), amortization (25 years) and down payment set by the Loaa & Manseur team for illustration, compiled October 13, 2026. This calculation is not financial advice; have it redone on the building you are considering, with its documents. The hub is a plex profitable, 19 cities compares the 19 cities.
Our other plex series in Longueuil, from the same Centris listings:
- Investing in a plex in Longueuil in 2026: price, per unit, days, volume
- Plex days on market in Longueuil, ten years
- Mortgage payment on the median house in Longueuil, ten years
Each series is recalculated from actual sales or leases, aggregates only.
Our proof, not our promises
The Loaa & Manseur team, led by Lotfi Manseur and Loaa Al Daow, is the number 1 team at RE/MAX Platine in 2024 and 2025, 6th RE/MAX team in Quebec, 15th in Canada and in the global top 50 of large residential teams according to the official RE/MAX ranking, computed on actual transactions. Its Google profile counts more than 220 reviews with a 4.9 rating. Its offices are at 55 avenue de l'Équinoxe in Brossard, one bridge from the island, and every broker's licence can be checked in the OACIQ public register. Three things to verify yourself before calling us, and to demand of any other broker.
Also available in French: version française de ce guide.
Published September 7, 2026 by the Loaa & Manseur team, the number 1 team at RE/MAX Platine in 2024 and 2025, 6th RE/MAX team in Quebec, 15th in Canada and in the global top 50 according to the official RE/MAX ranking. Tell us about your project.