Construction liens are one of the most powerful — and most misunderstood — legal tools in Canadian construction law. If you hire a contractor to renovate your home or build on your property, every subcontractor, supplier, and labourer who contributes to that project may have the right to register a lien against your property if they're not paid — even if you've already paid the general contractor in full. This means you can pay the contractor everything you owe and still face liens from unpaid subcontractors, potentially forcing you to pay twice or face a forced sale of your property. Understanding lien rights before you sign a construction contract is essential.
What is a Lien Rights?
A construction lien (also called a builder's lien or mechanic's lien depending on the province) is a legal claim registered against a property's title by someone who has supplied work or materials to improve that property and has not been paid. The lien gives the claimant a secured interest in the property itself, not just a personal claim against the person who hired them. In Canada, construction lien legislation is provincial, with each province having its own Act governing lien rights, holdback requirements, and dispute resolution. The core principle across all provinces is that those who improve property should have security for payment.
Red flags to watch for
Most provinces require the property owner to hold back a percentage of each payment (typically 10%) for a specified period to cover potential lien claims. If your contract doesn't address this, you may not have funds available to satisfy liens if the contractor fails to pay subcontractors.
Without lien waivers (or statutory declarations that subcontractors have been paid), you have no proof that the people actually doing the work have been compensated. This is your primary protection against lien exposure.
If the contract requires you to pay 100% upon completion without maintaining the statutory holdback, you're in breach of the lien Act and fully exposed to subcontractor claims.
Substantial performance triggers important deadlines in lien legislation, including the deadline for registering liens. If the contract doesn't define or provide for certification of substantial performance, the timelines become uncertain.
While not directly about liens, an unlicensed or uninsured contractor creates heightened lien risk because they're more likely to have financial difficulties, leaving subcontractors unpaid and driving them to file liens.
Your legal rights
Construction lien legislation is provincial. In Ontario, the Construction Act (R.S.O. 1990, c. C.30, as amended in 2018) requires a 10% holdback, provides a 60-day lien period after the contract is completed or abandoned, and mandates prompt payment obligations. In British Columbia, the Builders Lien Act (SBC 1997, c. 45) provides a 10% holdback and a 45-day lien filing period. In Alberta, the Builders' Lien Act (RSA 2000, c. B-7) provides a 10% holdback and a 45-day filing period. Quebec uses a legal hypothec under the Civil Code of Québec (art. 2726-2728) with a 30-day registration period. Across all provinces, liens that are properly filed take priority over subsequent mortgages and may take priority over prior mortgages for the value of the improvement. The holdback is a trust fund — paying it out early can create personal liability.
Questions to ask before you sign
- 1What is the statutory holdback percentage in my province and does the contract comply?
- 2Will the contractor provide lien waivers or statutory declarations from all subcontractors before each payment?
- 3What is the process for certifying substantial performance?
- 4Is the contractor registered with the appropriate provincial licensing body?
- 5What happens if a subcontractor files a lien despite the contractor being paid?
- 6Does the contract include a dispute resolution mechanism for lien claims?
Disclaimer: This guide is for educational purposes only and does not constitute legal advice. Contract law varies by jurisdiction and individual circumstances. Always consult a qualified legal professional before making decisions based on this information.