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Who’s in control? Supreme Court of Canada addresses when an owner is an employer on a construction site

January 8, 2024 | Daniel Averbach

A construction site involves many actors: the owner, constructor, subcontractors and workers.  All have separate, but often overlapping, obligations under Ontario’s Occupational Health and Safety Act (“OHSA”) to protect health and safety on site. When an accident occurs, the Ministry of Labour, Immigration, Training and Skills Development (“Ministry”) will investigate to determine if any party failed to comply with its OHSA obligations. Under section 25(1)(c) of the OHSA, the “employer” is responsible to ensure compliance with all measures and procedures prescribed by the OHSA and its regulations.

The OHSA defines “employer” as: “a person who employs one or more workers or contracts for the services of one or more workers and includes a contractor or subcontractor who performs work or supplies services and a contractor or subcontractor who undertakes with an owner, constructor, contractor or subcontractor to perform work or supply services.”

A recent Supreme Court of Canada decision released on November 10, 2023,[1] addressed the question of when a construction site “owner” may be considered an “employer” under the OHSA, and in so doing interpreted the definition of employer to apply to an owner even when an owner does not control the workers on site.  The decision is troubling and has significant implications for Ontario construction site owners.

What happened?

The City of Sudbury (“City”) contracted with a constructor, Interpaving Limited (“Interpaving”), to repair a water main and repave streets. Interpaving was the general contractor on the project and provided its own employees to perform the work.  The City employed two quality control inspectors to inspect the project.

During construction, an Interpaving employee tragically struck and killed a nearby pedestrian with a road grader. A Ministry investigation concluded that, contrary to the requirements of the OHSA’s Construction Projects Regulation, there was no fence to separate the construction work from the public and no signaller present. The Ministry charged both Interpaving and the City as “employers” under the OHSA.

The City conceded it was an owner at the site and had sent its employees for quality control purposes.  However, the City disputed being characterized as an employer of the Interpaving workers on the site as it was not in control of how work was performed; this was Interpaving’s responsibility.

At trial, the City was acquitted on the basis that, while a party may be both constructor and owner, in this case the City lacked the requisite control over the project to be held liable as an employer.  The Ministry successfully appealed to the Court of Appeal for Ontario which found the City to be an employer because it employed the quality control inspectors who oversaw Interpaving’s workers.  Significantly, the Court of Appeal did not consider the very limited control the City had over Interpaving’s workers.

The City appealed to the Supreme Court of Canada which split 4-4.[2]  As a result of the ‘tie,’ the appeal was dismissed and the Court of Appeal decision stands.

Those in favour of the City being an “employer”

Four judges dismissed the appeal on the basis the City was appropriately considered an employer of the Interpaving workers on the site.  According to those judges, the purpose of occupational health and safety legislation is to protect health and safety in the workplace and, to do so, the act places overlapping responsibility on various workplace actors, i.e., a “belt and braces” approach.  As such, a project owner will be an employer for the purpose of the OHSA if it employs workers on a site or contracts for the service of workers on the site, regardless of ‘control’ over the workers.

This interpretation is consistent with the plain language definition of employer under the OHSA, which does not import a requirement of control.  That said, the degree of control may be relevant to a due diligence defence which an employer may subsequently argue.

Those opposed…

Four judges held the City should not be considered an employer of the Interpaving workers under the OHSA.  In their view, the definition of employer is intended to cover both a traditional employer-employee relationship and where an entity directly contracts for services.  However, the definition is not intended to cover a situation where a project owner retains another party – such as a constructor – to undertake a project.

According to these judges, it would be ‘absurd’ to require an owner to be responsible for workers hired by a constructor, when the owner has no control over those workers.  Particularly in the construction industry, where there are often several contractors and sub-contractors each performing their own specialized work, it is practically impossible for a project owner to be responsible for each and every worker, and this would lead to endless charges without a proper basis.

Takeaway for employers

The split decision of the Supreme Court of Canada means the Court of Appeal decision stands and the definition of “employer” may apply even when a project owner has no control over workers on site.  This is troubling both in terms of legal implications and practical application.  However, for now, it remains the law of Ontario.

To mitigate risk, project owners should be familiar with the duties of an employer under the OHSA, and appropriately screen, select, and monitor contractors, to the extent reasonable.  This might include reviewing a contractor’s safety records and training protocols and any steps being taken to ensure ongoing compliance with health and safety standards.

To learn more, contact the health and safety lawyers at Sherrard Kuzz LLP.

Dan Averbach and Luiza Vikhnovich are lawyers with Sherrard Kuzz LLP, one of Canada’s leading employment and labour law firms, representing employers.  Dan and Luiza can be reached at 416.603.0700 (Main), 416.420.0738 (24 Hour) or by visiting  

The information contained in this presentation/article is provided for general information purposes only and does not constitute legal or other professional advice, nor does accessing this information create a lawyer-client relationship. This presentation/article is current as of December 6 2023 and applies only to Ontario, Canada, or such other laws of Canada as expressly indicated.  Information about the law is checked for legal accuracy as at the date the presentation/article is prepared but may become outdated as laws or policies change.  For clarification or for legal or other professional assistance please contact Sherrard Kuzz LLP.

[1] R v Greater Sudbury, 2023 SCC 28 (CanLII).

[2]     Ordinarily, nine Supreme Court of Canada judges decide a matter to avoid a split decision.  In this matter, for reasons not relevant to the decision, eight judges decided the matter.

Daniel Averbach Direct: 416.603.6951
Daniel Averbach Sherrard Kuzz LLP


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