Plex Housing as the Montreal Model

Madeleine Anderson

Abstract

Montreal’s triplexes are an emblem of the city’s architectural style, contributing to the diverse, dense, and dynamic character of the city. Built mainly in the late 19th century, plexes have stood the test of time as an efficient yet comfortable housing option. The vertically stacked apartments foster rental dynamics which support upward mobility, offering an affordable housing solution which promotes diversity. Additionally, plexes are designed for density at the human scale: their external staircases make individual units ground-oriented and provide a sense of independence while also fostering dense and highly walkable neighbourhoods. In an increasingly expensive and inaccessible housing market, the Montreal plex housing model is a form which could pose innovative and sustainable solutions for the densification of other cities.

Along with Habitat 67, the Notre Dame Basilica, and the Olympic stadium, Montreal’s rows of unique plex apartments have become an emblem of the city’s architectural style. The outdoor staircases that climb, coil and curve along Montreal’s residential streets give the city a truly unique flair, making it stand out among other North American cities. Built most intensely in the late 19th century, the dwelling style has stood the test of time, despite increasing trends towards suburbanization or high-rise apartment buildings seen in other cities. In an increasingly expensive and inaccessible housing market, the Montreal plex housing model is a form which could pose innovative and sustainable solutions for the densification of other cities.

The inspiration for this paper comes from my own third floor triplex apartment in the Mile End, which I adore living in for both the apartment itself as well as the energy of the neighbourhood. Love them or hate them, the plexes are a quintessential experience as a renter in Montreal, and their history and influences make them a truly Montrealspecific architectural phenomenon.

What is a Plex?

The term plex is derived from the suffix of the types of multi-family stacked housing most common in Montreal; duplexes having two units, triplexes having three units, and multiplexes having generally four or six units, though many variations exist across the city. The two- or three-story buildings typically contain one apartment per story and those with three or more units have a distinct visual style due to their external staircases. The standard triplex has separate entrances for each unit; the bottom floor having access from the street, the second floor being accessible from an external staircase onto a shared balcony with the third floor, and the third unit generally having a second, internal staircase leading to the top (Fig. 1 & 3). Plexes are built on modest residential lots, generally 20 to 30 feet wide1 and form continuous facades, often along entire blocks (Fig. 2 & 3). By stacking units and sharing a wall with neighbouring buildings, plex buildings are able to efficiently conserve heat in the winter months, as heat is distributed upwards and not lost to the outside.2 Typically, units are laid out with bedrooms and living spaces in the front (street side), with the kitchen and laundry or other utility areas in the back, as well as access to a back balcony (Fig. 1). At the back, a narrow alleyway serves the rear of the buildings, where small backyards, parking spaces, or storage sheds can often be found. In addition to being energy-efficient, the openings at the front and rear of the units allows for optimal light distribution and through air flow, providing relief in the hot summer months. The form of the Montreal plex is unique for a variety of reasons; its external staircases and individual entrances to each unit, as well as the practice of vertical stacking (as opposed to traditional British townhouses). The social and economic backdrop in which these versatile buildings were constructed, as discussed below, ultimately shaped their iconic form.

How did Plex Housing Become so Ubiquitous in Montreal?

The largest building cycle of Montreal’s plexes took place in the late 19th century. Due to intense industrialization and urbanization, Montreal’s population almost tripled between 1870 and 1900.3 One or two large factories opened every year between 1842 and 1855,4 and consequently the housing stock grew from 12,000 to 65,000 households between

Sandrine Rastello, “The Plexes of Montreal Make Room for Change,” Bloomberg Citylab, August 4, 2021, https:// www.bloomberg.com/news/features/2021-08-04/ looking-to-rent-in-montreal-get-to-know-the-plex

2 Anne-Lise Charroy, “Montreal’s Triplexes: The ‘Plex,’” Dynamic Cities Project, accessed March 23, 2023, http://dynamiccities. org/inspirations Andrea Kennedy, “Montreal’s Duplexes and Triplexes,” The Fifth Column 10, no. 4 (2002): 64–69.

3 Jason Gilliland and Sherry Olson, “Claims on Housing Space in Nineteenth-Century Montreal,” Urban History Review / Revue d’histoire Urbaine 26, no. 2 (1998): 3–16; Kennedy, “Montreal’s Duplexes and Triplexes.”

4 David B. Hanna, The Layered City: A Revolution in Housing in Mid-Nineteenth-Century Montreal, Partage de l’espace, no. 6 (Montreal: Dept. of Geography, McGill University, 1986).

1860 and 1900.5 Additionally, the need for affordable housing for the working class was intensified by several fires which wiped out large swaths of the existing housing stock: of the recorded housing in 1950, 19% was wiped out by fire.6 Following the Great Fire of 1952, the city prohibited wood construction.7 Thus, not only was the existing housing stock depleted, but the supply and feasibility of affordable housing was constrained, as new laws required housing be built with more expensive materials, such as stone or brick.

Multi-family housing was a way in which more expensive and fire-safe housing could be affordable to working class families. Additionally, the vast majority of Montreal workers in the late 19th to early 20th centuries walked to work, making urban sprawl an unfeasible option. The stacked dwelling thus became an obvious solution to the intense need for housing in Montreal at this time.

The plex’s unique exterior staircase was derived from a variety of cultural phenomena. It allowed for multiple stacked units to have their own entrances from the outside and for each unit to have its own street address. Separate entrances, along with balconies and platforms were favourable for families who moved from the countryside into the city, as they were reminiscent of the porches on their country homes.8 This also allowed residents to live in a dense urban environment while retaining a sense of privacy and independence. The external staircase was inspired by older duplex houses in Quebec, which were freestanding houses, but which featured an outdoor staircase which allowed upstairs tenants to have a separate entrance from the downstairs. Another reason for the separate entrances was the influence of the catholic church; it was frowned upon that multiple households should share a common entrance, because any number of sinful activities could happen in these liminal, unsupervised spaces.9 neighbourhoods a distinctly French flair, the vast majority of plexes were built with a flat roof, maximizing space and cost efficiency.

More practically, the external staircase saved money on utility costs, as it resulted in one less interior space that required heating. The city also implemented building setback rules, which required that the foundations of buildings be a certain distance from the sidewalk, for sanitation and crowding reasons. This led to builders opting to put staircases on the outside, to optimize living space without breaking any building codes.

The Social Dynamics of Plex Housing

5 Gilliland and Olson, “Claims on Housing Space in NineteenthCentury Montreal.”

6 Hanna, The Layered City

7 Paul-André Linteau and Peter McCambridge, The History of Montréal: The Story of Great North American City (Monteal, UNITED STATES: Baraka Books, 2013), http://ebookcentral. proquest.com/lib/mcgill/detail.action?docID=1162758

8 Kennedy, “Montreal’s Duplexes and Triplexes.”

9 Rastello, “The Plexes of Montreal Make Room for Change.”

10 Hanna, The Layered City

11 Kennedy, “Montreal’s Duplexes and Triplexes.”

12 Kennedy.

Though plex buildings share the recognizable features previously mentioned – stacked units, outdoor staircases, narrow but deep lots, back lane access – there is great variation of layout, materials, and exterior ornamentation across the city. The blocks are highly customizable, with some having larger two-story units up top to accommodate larger families, or different creative staircase layouts and shared balconies. These buildings were mostly not built en masse by large companies (though some larger scale actors were involved10), rather by small builders who took inspiration from each other and put their own flare into the projects. Thus, despite the residential and even suburban applications of this housing type, much variation among buildings exists, creating idiosyncrasies which “set Montreal’s townhouses apart from their European counterparts”.11 The wealthier British-inspired townhouses were often differentiated with flamboyant facades and different types of cladding, such as red brick, glazed brick, or Greystone, whereas the French workingclass residences were “usually quite austere, with dormer windows and cornice details to provide some decorations on the mansard roof”.12 While the mansard roof gave certain

At the time in which plex construction peaked, Montreal was largely divided between French, English, and Irish origins, with few common institutions. According to David Hanna (1986), “ethnic division fostered a mutually disadvantageous competition”,13 keeping wages low and characterizing Montreal as a manufacturing city. Additionally, the ownership dynamics of the plexes reflected the hierarchical class structure in Montreal. Oftentimes one family would own the entire building and rent out the other units. In some duplexes, a smaller unit in the semi-basement would be an affordable option for low-wage workers, while the wealthier owners of the building lived up top. In triplexes, the owners might occupy the bottom floor, and leave the treacherous outdoor stairs to the tenants up top. This created a physical class hierarchy within Montreal’s streets, but also meant that people of various classes and occupations lived together in close proximity, a recipe for diversity. The practice of tenants and landlords living in the same building persists today, though it is now increasingly common for entire buildings to be rented by a landlord who owns multiple buildings, or for the ownership of plex buildings to split up in condominium style.

Plexes also fostered diversity by providing affordable houses for recent immigrants and becoming a space of social mobility. Originally, the majority of the plexes were owned by wealthier English and FrenchCanadian families who lived in one of the units, and the other units were rented out to newer immigrants, often of Italian and Lebanese origin. But when the original owners opted to relocate to single-family homes in the suburbs, this opened the opportunity for those Italian and Lebanese renters to own buildings and provide rental housing to a new wave of migrants to the city.14 In addition to the rental dynamics, plexes offer a form of high-density affordable housing designed at the human scale; they are ground-oriented and provide a sense of space and independence while enabling a high level of walkability and variability. In many cases, shops and establishments can occupy the ground floor, enriching neighbourhoods and promoting local businesses. Thus, the architectural form of the multiplex and the small-scale rental dynamics it fosters, has provided a vessel through which Montreal has been able to maintain its diverse, dense, and dynamic character for over 150 years.

The Plex in the 21st Century

Despite the classic triplex being a recognizable symbol of Montreal’s urban landscape and character, they were not granted any sort of special protection. In 1945, “the outdoor staircases were seen as unsightly” and a by-law was passed prohibiting them which initiated a new wave of apartment block and high-rise construction that lasted until the by-law was repealed in 1970.15 Without sufficient protection, the original stock of downtown townhouses is being swept away to make room for new developments.16 However, despite some new trends in housing, plexes remain the most common housing type in Montreal, especially in trendy central districts such as the Plateau and Little Italy (Fig. 5). The cultural and economic benefits of plexes are continuously seen, making maintenance and renovation of older buildings as well as the construction of new, modern multiplex housing an attractive option. In 1997, the Canada Mortgage and Housing Corporation conducted research on the viability of plex

13 Hanna, The Layered City.

14 Konrad Yakabuski, “Triplexes Help Keep City Vibrant,” The Globe and Mail February 20, 2004, https://www.theglobeandmail.com/ real-estate/triplexes-help-keep-city-vibrant/article994172/; Hanna, The Layered City

15 Yakabuski, “Triplexes Help Keep City Vibrant.”

16 Kennedy, “Montreal’s Duplexes and Triplexes.” housing revitalization projects, finding that the “renewal of plex housing as a viable model is not only possible, it is also highly desirable, due to its many social, economic, environmental and sustainable development benefits”.17 With the demands for space per person in apartments increasing over the decades, many triplex buildings have been renovated and remodelled to increase space, or to simply update the facilities. The signs of this kind of update can be seen in my own triplex apartment, where the original walls were knocked down to create a larger, open living room where there was once a corridor connecting many smaller rooms. Additionally, examples of modern multiplex projects fit seamlessly with the pre-existing stock of plexes and are a viable model for new residential development (Fig. 7).

The Montreal Model could thus also be considered as a solution for other cities in need of densification. With cities growing and the demand for housing increasing, densification is a favourable option to urban sprawl, which brings with it a host of economic, environmental, and even health problems. The triplex offers a medium density housing solution which can accommodate up to 350 persons per hectare,18 promoting social interaction and diversity while still retaining a sense of place and independence. For example, Figure 8 compares a standard Montreal triplex to a typical Vancouver lot. The triplex is medium density housing at the human scale: dense enough to be within walking distance from all necessary amenities and to have a lively neighbourhood culture, and dispersed enough that units can have their own front door, not needing elevators to reach your apartment.

17 Canada Mortgage and Housing Corporation (CMHC), “‘Plex’ Housing : A Renewed Tradition,” Research Highlight. Technical Series 01-102 (Ottawa, July 1, 2002), https://publications.gc.ca/ site/eng/408767/publication.html, 4.

18 Charroy, “Montreal’s Triplexes: The ‘Plex.’”

References

Broudehoux, A.-M. (2019). Montrealism or Montréalité? Understanding Montreal’s Unique Brand of Livability. In Community Livability (2nd ed., pp. 3–15). Routledge.

Canada Mortgage and Housing Corporation (CMHC). (2002, July 1). “Plex” housing: A renewed tradition https://publications.gc.ca/site/eng/408767/publication.html

Charroy, A.-L. (n.d.). Montreal ’Plex. Dynamic Cities Project. Retrieved April 11, 2022, from http:// dynamiccities.org/inspirations

Gilliland, J., & Olson, S. (1998). Claims on Housing Space in Nineteenth-Century Montreal. Urban History Review / Revue d’histoire Urbaine, 26(2), 3–16.

Hanna, D. B. (1986). The layered city: A revolution in housing in mid-nineteenth-century Montreal. Dept. of Geography, McGill University.

Kennedy, A. (2002). Montreal’s Duplexes and Triplexes. The Fifth Column, 10(4), 64–69.

Linteau, P.-A. (2013). The History of Montréal: The Story of Great North American City (P. McCambridge, Trans.). Baraka Books. http://ebookcentral.proquest.com/lib/mcgill/detail. action?docID=1162758

Oh The Urbanity! (2020, October 26). Montreal’s Medium-Density Multiplex Neighbourhoods. https://www.youtube.com/watch?v=Vsn0ahdfQ9k

Rastello, S. (2021, August 4). The Plexes of Montreal Make Room for Change. Bloomberg CityLab https://www.bloomberg.com/news/features/2021-08-04/ looking-to-rent-in-montreal-get-to-know-the-plex.

Yakabuski, K. (2004, February 20). Triplexes help keep city vibrant. The Globe and Mail. https:// www.theglobeandmail.com/real-estate/triplexes-help-keep-city-vibrant/article994172/.