From Use to Form: Rethinking What Zoning Should Really Regulate

Canada’s housing crisis is intensifying, yet outdated zoning laws limit our ability to respond effectively. These regulations were built for an era when the nuclear family was the default, and anyone who didn’t fit that mold had limited housing options. To make real progress, we need zoning policies that reflect the reality of how Canadians live today, supporting more homes and more types of homes.   

Nuclear family in the 1950s by Jerome G. Rozen

Right now, our current housing mix is failing our communities. Prospective home buyers are trapped between three extremes: tiny “shoebox” apartments, a house out in the suburbs, or a pricey high-end home. Meanwhile, “missing middle” options including buildings that don’t fit traditional labels like “triplex” or “townhouse” are scarce. One example of this ‘misfit’ typology is a 6-unit building like the image below, that represents the kind of diverse housing our neighborhoods need but rarely see.

Halifax’s permitted building types in their Established Residential (ER-3) zone allowing small multi-unit dwellings (up to 8 units)

Young families need multiple bedrooms and retirees looking to downsize often want to remain in the same neighbourhood. This lack of diverse housing contributes not only to affordability challenges, but also to social isolation, a diminished sense of community identity, and increased dependence on cars.

Limits of Use-Based Zoning and the Federal Response

Typical zoning by-laws restrict neighbourhoods to single-detached, semi-detached, or townhouse dwellings (now with additional dwelling units), or set a maximum number of units per lot. This traditional use-based zoning (also known as Euclidean Zoning) limits not just the types of housing that can be built, but also the mix and building orientation, directly restricting the design options and business model for infill housing.

In contrast, France, Germany and Denmark have long embraced more flexible tools, such as Floor Area Ratios and height controls, enabling a broader mix of housing and land uses. And encouragingly in Canada, cities such as Edmonton, Sault Ste. Marie, Ottawa, and Halifax are departing from typology-based residential zoning, adopting policies that allow for a greater mix of housing. 

As municipalities move toward more diverse forms of low-rise infill, we need to let go of outdated regulations that focus on use and unit count, and rather focus on zoning the physical form of buildings.

Example of a 12–16-unit residential building with a mix of bachelor to 3-bedroom units from BuildingIN’s housing catalog.

The good news is the federal government has already recognized low-density zoning as a major barrier to housing and has made zoning reform a condition for Accelerator Funding. This means that to qualify, municipalities are required to allow at least four units in low-density areas. However, this upzoning can be challenging and not straightforward to implement. Because existing regulations were written around traditional typologies, overlapping zoning rules can create confusion and ambiguity when it comes to defining and permitting these additional dwelling units within traditional typologies. This lack of clarity can stall approvals and push developers toward projects with more predictable outcomes.

Tracing the Immoral Multi-Unit Housing Bias in Early Zoning

To understand why Canadian zoning feels so constraining today, it’s helpful to examine its origins.

In the late 19th and early 20th centuries, concerns about overcrowding in inner-city areas fueled a backlash against apartments, rooming houses, and boarding houses. Influenced by Ebenezer Howard’s Garden Cities movement which promoted locating single-family homes far from industrial areas and reinforced by widespread stigma against apartment living, Canadian cities increasingly saw low-density expansion growth as the ideal solution.

Industrial workers in the early 20th Century

In 1912, Toronto banned apartments in most residential neighbourhoods, driven by fears that they were “insanitary, anti-family, and a threat to established property values” (Dennis, 1998).  This ban disproportionately affected low-income groups such as single women, minorities and immigrants (Case, 2019). In comparison, Danish rental laws allow renters to sublet up to 50% of their unit as-of-right, with no blanket bans on rooming houses or the like. This is one example of how Canadian policies restricted affordable housing options for vulnerable populations, while other countries have taken a more inclusive approach.

By 1946, the Township of North York had gone so far as to explicitly zone for ‘families’—defined strictly as related residents—excluding unrelated individuals from living together. This gendered policy essentially barred lower-income women, who frequently shared accommodations with other single women, from accessing stable housing (Case, 2019).

Today, few people would consider apartments or multi-unit housing as an immoral or undesirable way of living. On the contrary, there’s broad recognition that we urgently need more homes, and homes of all types, especially considering that 21% of Canadian households with roommates or extended family report living in crowded conditions. With this shift in attitude, it’s worth asking: are our zoning rules holding us back from a more inclusive future?

Where We Stand Today

Driven by past influences and other factors, there was widespread adoption of single-family zoning, creating vast areas reserved exclusively for detached homes—what is now known as the “yellow belt.” In 2022, the School of Cities produced maps of major Canadian cities, showing that over half of their residentially zoned land was restricted to single-detached housing.

Residential typology maps of major Canadian cities from the School of Cities, 2022.

Edmonton is the outlier here, with much less single-family zoning than other municipalities. Many of these municipalities are heading in the right direction and have zoning changes underway by permitting fourplexes as-of-right in residential zones. Building on this progress, a coordinated approach—one that addresses zoning, building codes, and other regulatory hurdles—is crucial to ensure these changes translate into real housing options for more people.

The Form-Based Zoning Alternative

A simple way to achieve the more flexible housing design solutions we need is through form-based zoning, rather than simply adding additional unit permissions. Instead of asking, “What type of residential typology would be appropriate?” it prompts questions like, “How does the building’s street-facing design contribute to the character of the street?” and “How does its form and function fit within the neighbourhood and affect neighbours?”

To see how form-based zoning can work in practice, consider BuildingIN's work with Greater Sudbury and Ottawa. Both cities have zoning bylaw reforms underway to incorporate this more flexible and diverse approach to residential zoning. In neighbourhoods designated as suitable for infill development, these new rules allow up to 12 units per building while maintaining neighbourhood character through carefully designed controls. Some may worry that this flexibility could cause overcrowding on smaller lots. To prevent this, the zoning includes controls on maximum building size, height limits, required setbacks, landscaped area, and Floor Space Ratio, ensuring a balanced built form that respects neighbourhood character.

Example of a 6-unit building from BuildingIN’s Housing Catalog.

It's also important to highlight that the lot size naturally limits the number of units that can be built, meaning development is scaled to the site’s capacity. This approach maximizes the potential of existing infill lots without overbuilding, allowing market demand—not excessive regulation—to guide housing supply. This balance helps create diverse, well-integrated housing options while maintaining community fit and livability.

Embracing Change for Our Neighbourhoods

We understand that change is scary, and that use-based zoning feels “safe” because it’s what’s been done in the past and it’s predictable. But this safety is failing our communities and only exacerbating the housing crisis. It’s not just a matter of supply, but rectifying the mismatch of what housing is needed in Canada’s growing regions.

By adopting form-based zoning, cities can reposition themselves to be more flexible and adaptable in the face of ongoing changes, whether those changes are driven by shifting market demands, demographic trends, or unforeseen challenges. By focusing on the physical form and function of neighbourhoods rather than prescriptive land uses, municipalities gain the ability to respond more nimbly to evolving needs and opportunities, ensuring that communities remain vibrant and resilient over time.

Sources:

1.        Dennis, R. (1998). Apartment Housing in Canadian Cities, 1900-1940. Urban History Review/Revue d'histoire urbaine, 26(2), 17-31. https://doi.org/10.7202/1016656ar

2.       Cheryll Case, A Woman’s Right to Housing, House Divided, 2019, pg. 167-173

3.       Cheryll Case, A Woman’s Right to Housing, House Divided, 2019, pg. 168

4.      School of Cities. (2022). Yellowbelt: Canadian cities 2022. https://schoolofcities.github.io/yellowbelt-canadian-cities-2022/

5.       Richard Harris, Unplanned suburbs: Toronto's American tragedy, 1900 to 1950, Johns Hopkins Univ Pr, 1996, pg. 94-98

6.      Richard Harris, Unplanned suburbs: Toronto's American tragedy, 1900 to 1950, Johns Hopkins Univ Pr, 1996, pg. 97