Montreal's Substandard Housing: Three Boroughs, Three Stories

Not one ranking, but three

Since January 2024, the City of Montreal's Service de l'habitation has been systematically inspecting rental buildings with 6 or more units in socially vulnerable areas. Inspectors rate six components under European standard NEN 2767-1, on a scale from 1 (excellent) to 6 (end of life): foundation, building envelope, windows and doors, projections, interior, and structural frame^[7]. Of 1,932 buildings inspected, 185 scored 3 or higher on average - 10% of the inspected stock.

The obvious question is: which boroughs are the worst? And the honest answer is: it depends on what you measure. The chart above shows the share of inspections with a high score (3+, meaning buildings with major issues): LaSalle (11%), Le Sud-Ouest (10%), and Mercier - Hochelaga (7%) lead. But if instead you look at each borough's average score, the ranking flips:

This time, Lachine tops the chart (2.45 out of 6), followed by LaSalle (2.44) and Le Sud-Ouest (2.43). Lachine, which sat near the bottom on the previous metric (3% of buildings at 3+), now leads. How can both be true?

The two metrics actually measure different things. Average score captures the breadth of fatigue across the stock: how many buildings drift in the "mediocre but not catastrophic" zone. Share at 3+ captures the concentration of urgent cases: how many buildings have tipped into the problematic zone. A stock can be uniformly aged (high average, few extreme cases) or polarised (modest average, but a tail of bad buildings). Lachine, LaSalle and Le Sud-Ouest illustrate these two profiles.

Lachine: uniformly fatigued, the canal's legacy

Lachine is the cleanest case of "uniformly fatigued stock". Many buildings sit around 2 to 2.5 on the scale - mediocre but not in the critical zone. Very few tip into 3+ (3%). Why? Because the entire stock is ageing together.

Between 1850 and 1950, the shores of the Lachine Canal hosted one of Canada's largest industrial concentrations - nearly 600 companies established there, including giants like Dominion Bridge (1883) and Dominion Wire^[10]. The rental buildings constructed to house factory workers, many before 1950, make up most of today's housing stock in the area^[9]. The canal's closure in 1970 accelerated deindustrialisation and stalled building renovation. These century-old structures wear down at a similar pace - same materials, same freeze-thaw cycles, often the same local landlords doing the minimum without renovating in depth.

Le Sud-Ouest: pre-1946 stock polarised by gentrification

Le Sud-Ouest shares Lachine's industrial heritage - Saint-Henri, Pointe-Saint-Charles, Petite-Bourgogne, Griffintown, Côte-Saint-Paul and Ville-Émard all grew around the canal between 1850 and 1930. It is in fact the borough with the highest share of pre-1946 housing in Montreal: 33.8%, according to the City's sociodemographic profile^[13]. But unlike Lachine, Le Sud-Ouest shows a polarised profile: comparable average score (2.43) but 10% of buildings at 3+.

The explanation comes down to one phrase: asymmetric gentrification. Le Sud-Ouest is further along its transformation cycle than Lachine. A significant part of the old stock has been converted into upscale lofts (Griffintown, Pointe-Saint-Charles) or renovated for wealthier buyers, while another part remains a working-class rental stock that landlords are not investing in. The result is a bimodal distribution - heavily renovated on one side, badly neglected on the other - rather than uniform decline. The century-old triplex that collapsed in Saint-Henri in August 2024, without casualties, illustrates the neglected side of this polarisation^[3].

POPIR-Comité Logement, defending tenants in Saint-Henri, Petite-Bourgogne, Côte-Saint-Paul and Ville-Émard since 1969^[14], and the study Portrait de l'habitation à Pointe-Saint-Charles published by the local community centre in 2021^[15] have long documented this reality: mould, humidity, vermin, absent landlords. According to McGill civil engineering professor Daniele Malomo: "Old buildings in Eastern Canada have been built using non-engineered traditional construction techniques and do not feature the necessary structural details to withstand relevant vibrations."^[4]

LaSalle: the legacy of post-war walk-ups

LaSalle tells a completely different story. It is not a pre-war stock. It is a 1950s-60s stock, born of the post-war suburban boom. The emblematic case: LaSalle Heights, a 678-unit low-income rental complex built in 1955-56 by LaSalle Heights Inc. at the corner of Bergevin and Jean Milot streets^[12]. A whole generation of low-rise apartment buildings - the four- and five-storey "walk-ups" - was built in the same era to house immigration and a growing working class.

Today, LaSalle is 64% renters (against 62% for Montreal) and 19% aged 65 or over - a population largely renting in a stock that is now 60 to 70 years old^[11]. That age explains the polarised profile: 1950s-60s concrete-and-brick walk-ups age in jolts. As long as systems - roofing, envelope, concrete balconies, plumbing - hold, the building looks fine. When a system fails, the decline is rapid and catastrophic - not the gradual decline of a century-old red-brick duplex.

On top of this comes a different ownership structure: post-war walk-ups are typically held by absent landlords with several buildings, unlike the Plateau triplexes often owned and lived in by their owners. Less day-to-day maintenance, more accumulated backlog. That is how LaSalle ends up with the highest share of buildings at 3+ in all of Montreal (11%) while having an average score nearly identical to Lachine's.

The shared signal: full inspections

A third angle confirms how coherent these two different profiles are: the full inspection rate, that is, the share of buildings inspectors actually entered to assess interior spaces. This is not automatic - it means initial external signs were concerning enough to push the investigation^[8].

Lachine (38%) and LaSalle (33%) dominate this ranking by a wide margin, against 10% in Rivière-des-Prairies. The two tell the same thing for different reasons: in Lachine, the generalised wear of the century-old stock multiplies the signals; in LaSalle, the sudden failures of ageing walk-ups do. In both cases, a deteriorating balcony or a failing envelope is not always visible from the sidewalk - and the inspector has to push the door. Among the six components evaluated, projections (balconies, railings, cornices) are consistently the most deteriorated: 46% of buildings score 3 or higher on this element.

The Propriétaire responsable program, launched in March 2024 with a budget of $3 million over 3 years, aims to eventually cover 130,000 units in socially vulnerable zones^[2]. In 2024, according to Le Devoir, 3,559 units were inspected and 60 landlords were convicted, totalling $51,625 in fines - an average of $875 per conviction^[1]. "For profitable landlords, that's barely a month's rent," said Michel Proulx of the Comité logement Ahuntsic-Cartierville^[1].

A transparency tool for tenants - with its limits

The map covers only a fraction of Montreal's rental stock. The 1,932 buildings represent less than 0.5% of the roughly 400,000 rental units on the island. The program prioritises areas of high social vulnerability - results reflect the highest-risk zones, not the city as a whole. A building absent from the map has not necessarily been inspected and found in good condition: it may simply not have been visited yet.

Preventive inspections assess the exterior and common areas. They do not measure mould, excessive humidity, or heating problems - the issues most frequently reported by tenants. According to Montreal's public health directorate, one in three Montreal tenant households lives with at least one habitability problem^[6].

Despite these limits, the publication of geolocated inspection data is a genuine step forward. For the first time, a Montreal tenant can check whether their building has been inspected, what score it received, and whether a full inspection took place. It is a transparency tool - and potentially a lever for pressure - that tenant rights advocates had long been calling for.