Construction liens are an essential part of the construction industry in Ontario. They serve as a legal means for contractors, subcontractors, and suppliers to ensure payment for the services and materials they have provided. This article provides an overview of construction liens in Ontario, focusing on the legal framework established by the Construction Act, RSO 1990, c.C30.

What are Construction Liens?

Construction liens, also known as mechanic’s liens, are legal claims used by contractors, subcontractors, workers, and material suppliers to secure payment for their services and materials. These liens make the property collateral against the amount owed, preventing the property title from being transferred until the lien is satisfied or removed. Rules and procedures vary by jurisdiction.

The Construction Act, formerly known as the Construction Lien Act, provides a statutory framework for construction liens in Ontario. This Act has undergone significant amendments to better address the needs and practices of the modern construction industry. Key provisions of the Act include:

  1. Lien Entitlement: Contractors, subcontractors, and suppliers are entitled to a lien against the property they have worked on or supplied materials for as security for payment.
  2. Lien Registration and Timelines: The Act specifies strict timelines for preserving (registering) and perfecting (enforcing) a lien. Typically, a lien must be preserved within 60 days of the project’s substantial completion and perfected within 90 days of preservation.
  3. Holdback Requirements: The Act requires property owners to hold back 10% of the contract price, which must be released only after the lien period expires. This ensures funds are available to address potential lien claims.

Impact of Construction Liens

Construction liens have a significant impact on various stakeholders in the construction process:

  1. Contractors and Suppliers: Liens provide a mechanism for contractors and suppliers to ensure payment for their services and materials.
  2. Property Owners: For owners, liens represent a potential risk to their property title and may impact financing and project timelines.
  3. Construction Project Management: Liens can influence project cash flow and require careful financial management to ensure all parties are paid, and lien rights are addressed.

Best Practices for Managing Construction Liens

  1. Timely Payments: Adhering to the prompt payment provisions of the Construction Act can help in minimizing lien claims.
  2. Proper Documentation: Maintaining detailed records of work and supplies and understanding contract terms are crucial for both preserving and challenging lien claims.
  3. Legal Consultation: It is advisable to consult with legal professionals specializing in construction law to navigate the complexities of the Construction Act and manage lien-related issues effectively.


Construction liens in Ontario, governed by the Construction Act, are crucial for securing payments in the construction industry. Contractors, suppliers, property owners, and project managers must understand these liens for successful project completion. Navigating construction liens requires legal compliance, proactive financial management, and professional legal advice.

business lawyer in Toronto can provide valuable legal guidance and help review, draft, or negotiate your construction contract. If you’re a business owner in Toronto, consider hiring a small business lawyer to help ensure that your business is legally protected.

The information provided above is of a general nature and should not be considered legal advice. Every transaction or circumstance is unique, and obtaining specific legal advice is necessary to address your particular requirements. Therefore, if you have any legal questions, it is recommended that you consult with a lawyer.