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Construction Contracts & Liens in Ontario
Contracts, holdbacks, prompt payment, liens and disputes under Ontario's Construction Act — for homeowners, contractors and subcontractors.
Construction projects run on a web of contracts — owner to general contractor, contractor to subcontractor, and supplier agreements layered on top — and Ontario's Construction Act adds its own rules on top of whatever the parties signed.
This hub covers the practical side of Ontario construction law: what a solid construction contract should include, how liens and holdbacks actually work, the prompt payment and adjudication regime, and what to do when a project goes sideways.
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Construction Liens in Ontario: How They Work and Filing Deadlines
What a construction lien secures, who can claim one, Ontario’s 60-day preservation and 90-day perfection deadlines, and what registering a lien does to title.
Holdback Requirements Under Ontario’s Construction Act
Covers the mandatory 10% holdback, why it exists, basic versus finishing holdback, when it becomes releasable, and annual or phased release on longer projects.
Prompt Payment Rules in Ontario Construction Contracts
Covers the proper invoice requirement, the cascading 28-day and 7-day payment timelines, notices of non-payment, and how the regime is meant to keep money flowing down the payment chain.
Interim Adjudication for Ontario Construction Disputes
Explains the fast interim adjudication process under the Construction Act — which disputes qualify, how notice and appointment work, the 30-day decision timeline, and how it differs from mediation, arbitration and litigation.
Home Renovation Contracts in Ontario: What to Include
Key terms every homeowner-renovator contract should cover — scope, pricing, milestone-based payment, permits, change orders, cleanup and warranty — plus red flags to watch for.
Subcontractor Agreements in Ontario
What a general contractor–subcontractor agreement should cover, including pay-when-paid versus pay-if-paid clauses, prompt payment, insurance and indemnities, and the lien rights subcontractors keep regardless of contract wording.
Construction Deficiency Claims in Ontario
How to tell a deficiency from normal wear, document it properly, use holdback as leverage, and the options available when a contractor won’t fix defective work.
Substantial Performance in Ontario Construction Projects
What substantial performance means under the Construction Act, how it’s determined, and why publishing a certificate starts lien deadlines and can trigger holdback release.
Change Orders in Ontario Construction Contracts
Explains why scope changes need a written change order rather than a verbal instruction, covering price, schedule and holdback impacts, the typical approval process, and the risks unrecorded extras create for owners and contractors alike.
Performance and Labour & Material Bonds in Ontario
Breaks down what a performance bond protects versus a labour and material payment bond, when bonding is typically required, and how a bond claim against the surety generally proceeds.
Discharging or Vacating a Construction Lien in Ontario
Walks through an owner’s options when facing a registered lien — paying it out, negotiating a holdback-based arrangement, or posting security to vacate the lien from title — plus what happens when a claimant misses the Construction Act’s deadlines.
Homeowner vs. Contractor Disputes in Ontario
Covers common flashpoints such as incomplete work, overruns, delays and quality, practical first steps, holdback and lien dynamics from the homeowner’s side, and escalation through Small Claims or Superior Court.
FAQ
Construction: frequently asked questions
What is a construction lien in Ontario?
A construction lien is a legal claim registered against a property's title that lets a contractor, subcontractor or supplier secure payment for work or materials they provided but weren't paid for.
What is a holdback under the Construction Act?
Owners are generally required to hold back a percentage of the contract price for a set period after substantial performance, specifically to cover potential lien claims from the work down the contract chain.
What does prompt payment mean in Ontario?
Ontario's Construction Act sets strict timelines for paying proper invoices and for addressing disputes over them, intended to keep money flowing down the construction pyramid instead of stalling at the top.
How long do I have to register a construction lien?
Lien rights are time-limited and the deadlines are strict, running from events like substantial performance or last supply of services or materials — missing the window generally means losing the lien right entirely.
Understand your agreement. Know your next step.
Ontario-wide, plain-English contract law information — built to help you make sense of your situation before you decide what to do next.