In Ontario, under professional engineering law and occupational health and safety regulations, an owner's duty of care towards subcontractors primarily falls under three key legal frameworks:
- Occupational Health and Safety Act (OHSA)
- Tort Law (Negligence)
- Contract Law
1. Occupational Health and Safety Act (OHSA)
The OHSA imposes duties on all workplace parties, including owners if they meet certain criteria. While owners are not always directly responsible for subcontractors, they may be considered constructors or employers under the Act, depending on their role.
If an owner hires multiple contractors for a project, they may be classified as a constructor and bear significant legal duties, including:
- Ensuring the safety of all workers, including subcontractors
- Complying with OHSA and its regulations (e.g., Construction Projects Regulation, O. Reg. 213/91)
- Coordinating health and safety measures on-site
Even if the owner is not a constructor, they still have a general duty of care to ensure:
- The site is reasonably safe for subcontractors
- Hazards are identified and mitigated
- Due diligence is exercised to prevent foreseeable risks
2. Tort Law (Negligence) – Duty of Care in Civil Liability
Under common law, an owner can be liable for negligence if:
- They owed a duty of care to the subcontractor
- They breached that duty (e.g., failing to address known safety hazards)
- The breach caused harm
Owners must take reasonable steps to ensure the subcontractor is not exposed to unreasonable risks. This includes:
- Providing a safe work environment
- Ensuring compliance with safety regulations
- Not interfering with the subcontractor’s work in a way that increases risk
If an owner fails to do so, they can face civil liability for injuries or damages.
3. Contract Law – Explicit Agreements and Liabilities
Contracts between owners and subcontractors often define responsibilities. However, even if a contract limits an owner’s liability, it cannot override statutory duties under OHSA or tort law.
Best practices include:
- Clearly defining safety responsibilities in the contract
- Ensuring subcontractors carry their own insurance and WSIB coverage
- Including indemnity clauses to allocate liability
Conclusion
In Ontario, an owner's duty of care towards subcontractors depends on their role and the nature of the project. If they act as a constructor, they have strict legal duties under OHSA. Even if they are not a constructor, they may still be liable under negligence law or contract law if they fail to provide a reasonably safe worksite.
Would you like me to expand on any specific aspect, such as case law examples or how this applies to engineering projects?