The Difference Between Residential and Commercial Construction
- coraliefortin076
- Aug 31
- 7 min read
When planning the construction or renovation of a house, cottage, or garage, one fundamental question must be clarified from the outset: is it a residential or commercial project? This distinction, far from being purely administrative, has a direct impact on construction standards, permits to obtain, professionals to consult, and costs to anticipate. At Plan Maison Québec, we guide our clients through these key steps to ensure the success of their project. In this article, we explain how residential and commercial differ, and why it is essential to understand this nuance to build in full compliance in Quebec.
Understanding the Basics: What is Residential Construction?
In the construction industry in Quebec, the distinction between residential and commercial projects is not solely a matter of building style or size. It is fundamental for planning, design, budgeting, and compliance with applicable standards. Residential construction generally refers to any project whose primary purpose is habitation: this includes single-family homes, semi-detached homes, cottages, townhouses, condominiums, and attached or detached residential garages. Each type of housing meets specific technical and regulatory standards, both at the municipal and provincial levels.
According to Statistics Canada's official definition, a dwelling is considered residential when its primary use is to serve as a permanent or temporary residence for individuals. This statistical definition includes physical characteristics (number of rooms, number of floors, type of foundation, construction materials, etc.) but is not sufficient on its own to distinguish a residential project from a commercial project, especially when dealing with large-scale or mixed-use buildings.
This is where Plan Maison Québec's expertise becomes a major asset for clients wishing to embark on the design of a custom plan. By taking into account the applicable legal and regulatory criteria, our team can guide you toward the appropriate technical framework from the earliest stages to avoid any confusion or project delays related to incorrect building categorization.
Key criteria according to the Quebec regulatory framework
In Quebec, the line between a residential and a commercial construction project is defined by well-established criteria that can sometimes surprise owners. Many of them mistakenly believe that a building is residential if it contains housing. However, this is not always the case.
1 . The main use of the building
The first criterion to consider is the building's primary use, that is, the function for which the majority of the surface area is intended. A multi-story building that primarily contains offices, a retail outlet, a clinic, or a public facility—even if it includes some residential units on the upper floors—will be categorized as a commercial or institutional building. This distinction is crucial because it determines the applicable design standards, as well as the safety, accessibility, and structural strength requirements.
2 . The proportion of spaces reserved for housing
The second fundamental criterion is the proportion of habitable space. A project is officially considered residential if at least 85% of the total surface area is dedicated to living space. As soon as this proportion falls below this threshold, the Régie du bâtiment du Québec (RBQ) classifies the project as a commercial or institutional building. This rule applies to both new construction and renovation projects.
At Plan Maison Québec, we analyze your needs and the planned layout of your building from the outset to help you meet this requirement. It is this type of strategic support that avoids costly revisions along the way or unforeseen administrative procedures.
3 . The number of floors above ground
The third factor is the number of floors in the building. For new construction, as soon as the project exceeds six floors above ground, it is automatically classified as a commercial or institutional building, regardless of the intended use. In the case of a renovation project, this threshold increases to eight floors. Note that only floors visible from the exterior are taken into account: basements are therefore generally not included in this calculation.
This rule aims to strengthen safety standards for high-rise buildings, which require more complex fire safety systems, redundant elevators, and more advanced passenger flow management. Plan Maison Québec takes these constraints into account from the design phase, integrating structural features related to the building's height into its plans.
Practical application: new or renovation?
The classification of a project as residential or commercial is not fixed: it can vary depending on whether it is a new construction or renovation project. The nature of the work and the physical characteristics of the building therefore directly influence the regulatory obligations to be met.
New construction
When a Plan Maison Québec client wishes to build a house, cottage, or apartment building, they must first verify whether the requirements for residential construction are met. If the project includes fewer than six stories and more than 85% of the floor space is reserved for residential use, the project is classified as residential. This opens the door to more flexible standards, generally shorter approval times, and lower design and execution costs.
However, if the building exceeds the six-story threshold or if commercial space is planned on the ground floor (e.g., a convenience store or professional office), the project must be treated as a commercial construction. In this case, Plan Maison Québec often collaborates with specialized engineers and architects to ensure full compliance with applicable requirements.
Renovation work
In the case of a renovation or expansion, the rules are similar, but slightly relaxed: the threshold increases to eight stories. If an owner wishes to convert an existing seven-story building into a residential condominium, they can still benefit from residential status, provided they comply with the minimum proportion of habitable space. If this limit is exceeded, structural, engineering, and ventilation adjustments may be required.
The Plan Maison Québec team has the expertise to quickly assess the feasibility of the project, determine whether it remains within the residential framework, and, if necessary, propose technical solutions that avoid falling under more restrictive regulations.
Mixed situations: specific challenges to anticipate
An increasing number of projects in Quebec are targeting mixed-use buildings, particularly in dense urban areas. It's not uncommon to see buildings with multi-story residential units, but with the ground floor occupied by retail, professional offices, cafes, or even community services. These hybrid configurations are increasingly popular for maximizing land profitability while meeting residents' proximity needs.
However, this functional mix considerably complicates building classification. The standards to be applied depend not only on the distribution of spaces, but also on the precise percentage of non-residential use, the expected traffic flow, the type of occupants, access to emergency exits, etc.
In this context, Plan Maison Québec acts as a strategic advisor to its clients. We conduct detailed feasibility analyses to determine the project's classification right from the design phase, avoiding unpleasant surprises when obtaining permits or during the intervention of municipal inspectors.
Why is this distinction vital for your project?
Properly classifying a residential or commercial project is not a simple administrative formality. It determines the entire development of the project: from the initial budget to the materials used, including the professionals to be hired, the necessary insurance, legal obligations, and even the tax rate applied to the property once completed.
For example, a project classified as commercial will likely need to incorporate accessible elevators, reinforced emergency exits, facilities for people with reduced mobility, and sophisticated security systems. These elements can significantly increase construction costs. In addition, certain specific permits or approvals will be required, which lengthens the construction timeline.
On the other hand, a project clearly defined as residential often allows for greater flexibility, particularly in materials, interior design, finishes, and speed of implementation.
Thanks to its in-depth expertise in the Quebec Construction Code and the RBQ, Plan Maison Québec is able to accurately and efficiently guide its clients toward the best decisions at every stage of the project.
Comparative summary according to cases
The summary of the criteria provides a better visualization of the boundaries between the two types of projects:
New construction
≥85% residential space: considered residential
≤6 visible floors: residential
If one of the criteria is not met: commercial project
Renovation
≥85% residential space and ≤8 floors: residential
Otherwise: commercial or mixed-use, subject to specific requirements
Mixed-use project
Detailed analysis required
Significance of the proportion of commercial or professional space
Support required from experts such as Plan Maison Québec
How Plan Maison Québec can support you
Plan Maison Québec is much more than just a plan designer. Our mission is to bridge the gap between your personal vision—a dream home, a rustic chalet, a modern duplex, or a functional garage—and the stringent requirements of Quebec's legal framework.
Using a rigorous and personalized methodology, we:
Identify the exact nature of your project (residential, commercial, or mixed-use) at the first meeting;
Design custom plans that comply with the standards of the RBQ, municipalities, and the Quebec Construction Code;
Collaborate with the appropriate technical stakeholders based on the chosen classification;
Ensure consistency between your personal objectives and legal, technical, and budgetary constraints.
Thanks to this approach, Plan Maison Québec helps you move forward with confidence, limiting unforeseen events and optimizing each stage of your project's completion.
Conclusion: difference residential commercial construction
Knowing the clear difference between residential and commercial construction is essential to avoid costly mistakes and ensure your project complies with current regulations. Whether you dream of a lakeside cottage, an urban duplex, or an expansion of your family home, rigorous planning that complies with Quebec regulations is the key to success.
Plan Maison Québec offers you professional, personalized, and tailored support to navigate this regulatory complexity. Our specialists are there to analyze your project, design perfectly tailored plans, and guide you toward the best decisions, from the first sketch to the building permit.
Together, let's build the future—one house at a time.
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