Adjudication, arbitration and litigation in Ontario

When a claim does not settle, Ontario parties have three main routes: adjudication under the Construction Act, arbitration, and court. They differ in speed, cost, finality and privacy, and each has deadlines that can end a claim if missed. This lesson compares them, with the timelines owners and contractors need to know.

Learning outcomes

• Describe the Construction Act adjudication process and its timelines.
• Explain the interim binding nature of an adjudicator's determination.
• Compare adjudication, arbitration and litigation on speed, cost, finality and privacy.
• Identify the limitation and contractual deadlines that apply to construction claims.

The lesson

Adjudication

Ontario's Construction Act, Part II.1, gives parties to a construction contract the right to refer certain disputes, mainly payment-related ones such as the valuation of services and materials, change orders, set-off and holdback, to adjudication [1]. The timetable is short: the respondent has 4 days to respond to the notice of adjudication; an adjudicator is appointed by consent or 7 days after a request to ODACC; the claimant delivers its documents 5 days after appointment; and the determination is due 30 days after those documents, unless extended by agreement [2]. The Act limits when a notice can be given; generally, not after the contract is completed unless the parties agree.

A determination is binding on an interim basis and enforceable as a court order until a court, an arbitrator or the parties' written agreement says otherwise. It cannot be appealed; judicial review needs leave, the amount ordered must be paid first, and the grounds are narrow [2]. ODACC data reported for 2023 showed 161 determinations from 269 notices [2].

Arbitration

CCDC 2-2020 Part 8 provides for negotiation and mediation, and for arbitration where the parties agree or the contract requires [3]. Arbitration in Ontario is governed by the Arbitration Act, 1991 [4]. It is private, the parties choose an arbitrator with construction expertise, and awards are final with limited appeal rights, depending on the arbitration agreement. It is also slower and more expensive than adjudication.

Litigation and limitation periods

Court is public, slow and expensive, but available where there is no arbitration agreement or for parties who need court powers. Under Ontario's Limitations Act, 2002, the basic limitation period is two years from the day the claim was discovered [5]. Contracts add their own deadlines, such as notice periods in Part 6 and dispute timelines in Part 8. Lien rights under the Construction Act run on their own, much shorter clock (see construction liens in Ontario).

Northgate worked example

Northgate Distribution Centre (fictional) is a 12,000 m² tilt-up warehouse in Vaughan, Ontario, built by Halvorsen Builders Ltd. (fictional) under CCDC 2-2020, with Ridgeline Architects Inc. (fictional) as Consultant. See the Northgate fact sheet. This course follows one delay claim from first notice to settlement. Ready-for-Takeover (M9) was due Friday, January 14, 2028 and was reached on Tuesday, March 14, 2028: 60 calendar days late. All events, dates and amounts are illustrative.

In early May 2028, before Ridgeline's findings, Halvorsen's lawyer advised that the acceleration head ($118,810) could be referred to adjudication as a payment dispute; deficiency work was still open, so the contract was not yet completed. An adjudication would have produced an interim determination in about six weeks, and the owner would have had to pay any amount ordered before challenging it.

Halvorsen chose to wait for the findings and negotiate, because its notice problem on the acceleration head (lesson 13) made an adjudication risky, and the cost of preparing for one was close to the amount in dispute. The owner, for its part, knew that withholding without a proper notice of non-payment would have handed Halvorsen an easy adjudication. Both sides' knowledge of the forum shaped the settlement in lesson 19.

Your move

If you are the owner

• Diarize every deadline. Notice of non-payment, Part 8 timelines, limitation dates.
• Prepare as if adjudication is coming. Organized records make a 30-day timetable manageable.
• Check the contract for arbitration. Know your forum before a dispute.
• Pay determinations when due. Challenge them properly, not by withholding.

If you are the contractor

• Use adjudication for payment disputes. It is fast and enforceable.
• Act before completion. Adjudication timing is limited.
• Weigh cost against value. Preparation is intense over a short period.
• Watch the two-year limitation period. And shorter contractual clocks.

Common mistakes

1. Missing limitation dates while negotiating. Get a standstill agreement in writing.
2. Treating adjudication as final. It is interim, but enforceable.
3. Ignoring a notice of adjudication. The timetable runs anyway.
4. Arbitration clauses nobody read.
5. Choosing the forum by habit. Match it to the dispute.

Quick quiz

1. How long does an adjudicator have to make a determination after the claimant's documents?

   1. 10 days
   2. 30 days
   3. 90 days
   4. 1 year

2. What is the status of an adjudicator's determination?

   1. Advisory only
   2. Binding on an interim basis and enforceable
   3. Final with no review
   4. Secret

3. What is the basic limitation period in Ontario?

   1. 6 months
   2. 1 year
   3. 2 years
   4. 6 years

4. Which forum is public?

   1. Adjudication
   2. Arbitration
   3. Litigation
   4. Mediation

5. Why did Halvorsen not adjudicate the acceleration head?

   1. It was not allowed
   2. The notice problem made it risky and preparation cost was close to the amount
   3. The owner refused
   4. It was too late

Show answers and explanations

1. B. 30 days, unless extended by agreement.
2. B. Binding until overturned by a court, arbitrator or agreement.
3. C. Two years from discovery under the Limitations Act, 2002.
4. C. Court proceedings are generally public.
5. B. Forum choice is a cost and risk decision.

Key terms

Adjudication

A fast, interim-binding dispute process under Ontario's Construction Act.

ODACC

Ontario Dispute Adjudication for Construction Contracts, the authorized nominating authority.

Determination

An adjudicator's decision, enforceable as a court order.

Arbitration

A private, final dispute process before an arbitrator chosen by the parties.

Limitation period

The time limit for starting a legal proceeding.

References

1. Government of Ontario, Construction Act, R.S.O. 1990, c. C.30, Part II.1 (adjudication).
2. Ivan Merrow and Andrew Kalamut, McCarthy Tétrault, Six takeaways from Construction Act adjudication: four years in review (December 15, 2023).
3. Canadian Construction Documents Committee, CCDC 2-2020 Stipulated Price Contract, GC 6.4 to 6.6 and Part 8. Clause content checked against a publicly posted tender copy; buy the form from CCDC.
4. Government of Ontario, Arbitration Act, 1991, S.O. 1991, c. 17.
5. Government of Ontario, Limitations Act, 2002, S.O. 2002, c. 24, Sched. B, section 4 (basic limitation period).

Verified on November 9, 2026.

Next lesson in this trackNorthgate capstone: a 60-day delay claim