Construction Law: Toronto & Ontario
Construction law is all we do.
Corestone Law is a Toronto litigation boutique serving owners, general contractors, developers, subcontractors, and suppliers across Ontario. When a dispute goes to court, adjudication, or arbitration, you want lawyers who spend every day in this practice area.
Page last reviewed: May 5th, 2026
Construction Liens Ontario
Construction Liens
A construction lien is a legal claim registered against a property title for unpaid services and materials supplied to improve that property. It is one of the most powerful collection tools available to contractors, subcontractors, and suppliers in Ontario, and one of the most deadline sensitive. In most cases, the preservation window is 60 days from last supply, completion, termination or abandonment of a contract. Once it passes, the right is gone permanently with no remedy.
For Contractors, Subcontractors and Suppliers
If you have not been paid for work performed or materials supplied, you are entitled to file a construction lien. While the lien is in place, any sale of the property requires your lien to be paid out or money must be put in court in lieu of the lien. Let us help you get the funds you are owed.
For Property Owners
If you have been served with a construction lien claim, which is called a “Statement of Claim”, time is critical. You have a limited window to file a Statement of Defence, and failure to respond within the required timeframe may result in being noted in default. Let us help you defend your property and assess your options.
Why Corestone Law
Why use Corestone Law for construction disputes?
For liens, registration and preservation deadlines are strict and missing them are fatal to the lien. Even after a lien is registered and perfected by issuing a Statement of Claim, there are deadlines on setting the lien matter down for trial. In addition, understanding construction contracts, holdback obligations, trust obligations require unique knowledge and expertise. We regularly register, perfect, vacate, prosecute and defend, construction liens across Ontario. This is not a practice area we dabble in; it is the core of what we do.
Lien issue?
Prompt Payment & Construction Act Adjudication Ontario | Updated 2026
Prompt Payment & Adjudication
Ontario’s prompt payment regime requires owners to pay general contractors within 28 days of a proper invoice, and general contractors to pay subcontractors within 7 days of receiving payment. When payments are disputed or withheld, adjudication provides fast, binding resolution typically within 30 to 60 days. The January 2026 Construction Act amendments expanded adjudication rights significantly. If you have received a Notice of Adjudication or need to initiate one, act immediately.
Services include:
- Proper invoice review and compliance
- Notice of non-payment analysis and response
- Adjudication as claimant or respondent
- Adjudication decision enforcement and challenge
- Prompt payment disputes involving owners, GCs and subcontractors
- Construction Act trust claims
Why Corestone Law
Why use Corestone Law for prompt payment and adjudication?
Adjudication under Ontario’s Construction Act is not arbitration and it is not court. It is a distinct statutory process with its own rules, timelines, and consequences that is best navigated by a Construction litigator. The January 2026 amendments expanded adjudication rights and the case law is still developing. We know the process and we know how to build a claim, or a defence, that holds up under the compressed timeline adjudication demands.
Adjudication or prompt payment issue?
Construction Contracts Ontario
Construction Contracts
Most construction disputes trace back to a poorly drafted or misunderstood contract term. Corestone Law reviews, drafts, and negotiates construction contracts for owners, general contractors, subcontractors, developers, and suppliers across Ontario. Whether the file involves CCDC 2, a stipulated price contract, or a custom GC to sub agreement, we identify the clauses that create exposure before work begins, not after a dispute.
Services include:
- CCDC 2, CCDC 5A and custom agreement review, drafting and negotiation
- Payment terms, holdback provisions and prompt payment clause analysis
- Scope of work, change order and variation clause disputes
- Termination for default and termination for convenience matters
- Delay and disruption claim preparation and defence
- Indemnification, limitation of liability and insurance requirement review
- AI generated contract clause liability (new: 2025 onward)
Why Corestone Law
Why use Corestone Law for construction contracts?
A construction lawyer does not just see a payment clause, they see a pay-when-paid provision, a holdback obligation under the Construction Act, and a potential prompt payment trigger in the same sentence. CCDC 2 and custom GC-to-sub agreements carry industry language that is complex. Construction contracts are the only contracts we deal with.
Contract issue?
Construction Tender Disputes Ontario
Tenders
The tender process creates legal obligations the moment bids are submitted. Ontario courts have held consistently that Contract A, the binding contract formed upon submission of a compliant bid, gives rise to enforceable duties on both owners and bidders. Corestone Law advises general contractors, subcontractors, and project owners on tender compliance, bid disputes, privilege clauses, and the legal consequences of non-award.
Services include:
- Contract A and Contract B analysis and dispute
- Bid exclusion and disqualification challenges
- Privilege clause scope and enforceability
- Public and private sector procurement disputes
- Lowest compliant bid and owner duty of fairness matters
- RFP and pre-qualification process disputes
Why Corestone Law
Why use Corestone Law for tender disputes?
Tender law sits at the intersection of contract law, procurement law, and construction industry practice. The duty of fairness owed to bidders, the scope of privilege clauses, and the enforceability of Contract A obligations are construction specific legal questions with a distinct body of Ontario case law behind them. We have litigated tender disputes. We know where owners and bidders each have exposure, and we do not confuse the two.
Tender dispute?
Contractor Disputes Ontario
Contractor Disputes
Disputes between contractors, subcontractors, and owners are common in construction. Corestone Law represents general contractors, subcontractors, and developers in disputes involving payment refusals, scope changes, termination for default, delay claims, and deficiency allegations. We handle these matters from demand letter through trial or arbitration.
Services include:
- Payment disputes and non-payment claims between contractors and owners
- Scope of work disputes and change order refusals
- Termination for default — both pursuing and defending
- Delay, disruption and acceleration claims
- Deficiency and defective work allegations
- Back-charges and set-off disputes
- Sub-trade payment disputes under Construction Act trust provisions
- Performance bond and labour and material payment bond claims
- Surety disputes
Why Corestone Law
Why use Corestone Law for contractor disputes?
A contractor dispute is not just a breach of contract claim. It involves Construction Act holdback obligations, lien rights that may be running in parallel, prompt payment timelines that may already be triggered, and often multiple parties whose claims interact in ways general litigators do not anticipate. Because we only practice construction law, we see the whole board from day one. We know which lever to pull first and why the sequence matters.
Construction dispute?
Small Claims Court – Construction Ontario
Small Claims
Not every construction dispute belongs in Superior Court, but every unpaid invoice deserves pursuit. Corestone Law handles Small Claims Court matters for contractors, subcontractors, and suppliers pursuing unpaid accounts. As of October 2025, the Ontario Small Claims Court limit increased to $50,000. We move efficiently, keep costs proportionate to the claim, and do not let procedural complexity become a reason to walk away from money you are owed.
Why Corestone Law
Why use Corestone Law for construction small claims?
A standard small claims matter is a debt. A construction small claims matter involves holdback calculations, lien rights that may still be available, prompt payment timelines, and the question of whether a demand letter or adjudication would have been a faster path to the same result. Getting that wrong costs more than the claim is worth. We assess the full picture before recommending the forum.
Owed money on a project?
OHSA Defence – Construction Ontario
Occupational Health and Safety in Construction
Construction sites are Ontario’s most heavily regulated workplaces. The Occupational Health and Safety Act imposes specific duties on owners, constructors, and employers that go well beyond general workplace requirements. When an incident occurs, a Ministry of Labour investigation follows quickly and the legal consequences for constructors and employers can be severe.
Services include:
- Ministry of Labour investigations and stop-work orders
- OHSA charges and regulatory defence for constructors and supervisors
- Critical injury and fatality investigations on construction sites
- Due diligence defence
- Workplace safety policies and compliance frameworks for construction firms
- Jurisdictional disputes between unions on construction projects
- Labour relations specific to the construction industry
Why Corestone Law
Why use Corestone Law for OHSA matters?
Most employment lawyers handle OHSA as a footnote. We do not. Construction sites
involve multi-employer workplaces, overlapping scopes of responsibility, and a regulatory framework, the Construction Projects Regulation (O. Reg. 213/91), that applies specifically to your industry.
Facing an OHSA matter?
Frequently Asked Questions
In most cases, a construction lien must be preserved within 60 days of the last supply of services or materials, completion, termination or abandonment of a contract. Deadlines vary depending on the contractual relationship between the claimant and property owner. Because the deadline is strict and missing it is permanent, contact a construction lawyer as soon as payment is withheld. Do not wait.
Adjudication is a fast, binding dispute resolution process under Ontario's Construction Act. In most cases it resolves within 30 to 60 days and is available for payment disputes between parties on a construction project. It is a distinct process from arbitration and court proceedings with its own rules and timelines.
Under Ontario’s prompt payment regime, owners must pay general contractors within 28 days of a proper invoice. General contractors must pay subcontractors within 7 days of receiving payment. A dispute over payment triggers the right to adjudication under the Construction Act. The January 2026 amendments to the Act expanded these rights further.
As of October 1, 2025, the Ontario Small Claims Court limit increased to $50,000. Construction contractors and suppliers can pursue unpaid accounts up to this amount through Small Claims Court, which is typically faster and less expensive than Superior Court proceedings.
Ontario’s Construction Act requires that a percentage of each payment be held back as a statutory holdback throughout the project. This holdback protects lien rights and trust obligations for contractors, subcontractors, and suppliers down the payment chain. The precise holdback percentage and release conditions depend on the contract and project type.
Corestone Law is a construction litigation boutique serving clients across Ontario. Practice areas include construction liens, prompt payment, Construction Act adjudication, construction contracts, tender disputes, contractor disputes, small claims, and OHSA defence for constructors. Construction law is the only area the firm practices.
Ready to speak with a construction law specialist?
Construction law is the only area we practice.
When you call Corestone, you reach a lawyer who already knows your industry, your contracts, and your options.