How does construction adjudication work in Ontario?
Under Ontario's Construction Act a party to a contract or subcontract can refer a payment dispute to an adjudicator. The notice of adjudication must be given within 90 days after the contract is completed, abandoned or terminated. The adjudicator determines the dispute within 30 days of receiving the documents, and the amount is paid within 15 days.
The adjudication, in order
- Give the other party a written notice of adjudication with the content the Act requires, and send a copy to the Authority the same day (s 13.7(1); O. Reg. 264/25 s 20), within 90 days after the contract is completed, abandoned or terminated. For a subcontract the 90 days run from the earliest of that date, the date the subcontract is certified complete under s 33, and the date the subcontractor last supplied (s 13.5(3.1)).
- If the adjudicator named has not consented within 4 days, the party who gave the notice asks the Authority to appoint one. The Authority appoints within 7 days after the request (s 13.9(5)).
- The party who gave the notice serves the contract and every document relied on within 5 days after the adjudicator agrees or is appointed.
- The adjudicator determines the dispute within 30 days of receiving the documents. Extendable before expiry by up to 14 days on the adjudicator's request with the parties' written consent, or by any period the parties agree in writing with the adjudicator's consent (s 13.13(2)); a party who gave a notice of non-payment on the matter must pass on notice of the extension (s 13.13(3), (4)).
- The amount determined is paid within 15 days after the determination is communicated. Any motion for leave to seek judicial review is filed within 35 days after the same day.
| Duty | Window and section | If missed |
|---|---|---|
| Give any notice of adjudication within 90 days after the contract is completed, abandoned or terminated | 90 dayss 13.5(1)-(3.1), (4), (5); O. Reg. 264/25 s 19 | the claim is barredDisputes |
| Give the other party a written notice of adjudication with the content the Act requires, and send a copy to the Authority the same day | none sets 13.7(1); O. Reg. 264/25 s 20 | no penalty statedDisputes |
| Ask the Authority to appoint a registry adjudicator if the agreed adjudicator has not consented within 4 days after the notice of adjudication | 4 dayss 13.9(2)-(6); O. Reg. 264/25 s 21, 22 | no penalty statedDisputes |
| Give the adjudicator the notice, and the adjudicator and the other party the contract and every document relied on, within 5 days after the adjudicator agrees or is appointed | 5 dayss 13.11; O. Reg. 264/25 s 24 | no penalty statedDisputes |
| Respond in writing to a notice of adjudication by the day the adjudicator specifies, copied to the adjudicator and every other party the same day | none sets 13.11.1; O. Reg. 264/25 s 25 | no penalty statedDisputes |
| Receive the adjudicator's written determination within 30 days after the adjudicator receives the documents | 30 dayss 13.13(1)-(6), 13.17.1; O. Reg. 264/25 s 30, 32 | a breach of contractDisputes |
| Pay any amount an adjudicator's determination requires within 15 days after it is communicated | 15 dayss 13.15, 13.19(1)-(6), 13.20 | a breach of contractDisputes |
| File any motion for leave to seek judicial review of a determination within 35 days after it is communicated | 35 dayss 13.12.1, 13.18(1)-(7) | the claim is barredDisputes |
| Refer the owner's non-payment to adjudication within 21 days after giving a subcontractor a notice of non-payment that undertakes to do so | 21 dayss 6.5(5)(a)(iii), 6.6(6)(a)(iii) | no penalty statedDisputes |
What the library notes on each duty
Quoted a whole sentence at a time from the library's note on each row.
Give any notice of adjudication within 90 days after the contract is completed, abandoned or terminated
s 13.5(1)-(3.1), (4), (5); O. Reg. 264/25 s 19 · 90 days · the claim is barred
- After the 90 days an adjudication may not be commenced unless the parties agree otherwise (s 13.5(3)).
- For a subcontract the 90 days run from the earliest of that date, the date the subcontract is certified complete under s 33, and the date the subcontractor last supplied (s 13.5(3.1)).
- This text is in force from 1 January 2026; the earlier text was not read.
- Adjudicable matters (O. Reg. 264/25 s 19): valuation, payment including change orders approved or not, any dispute in a notice of non-payment, set-off amounts, holdback payment under s 26, and scope, price change or extension of time where needed to decide one of those.
- One dispute per adjudication unless the parties and the adjudicator agree (s 13.5(4)), even if a court action or arbitration is under way (s 13.5(5)).
Give the other party a written notice of adjudication with the content the Act requires, and send a copy to the Authority the same day
s 13.7(1); O. Reg. 264/25 s 20 · none set · no penalty stated
- The notice states the parties' names and addresses, the nature of the dispute and how and when it arose, the redress sought, a proposed adjudicator, and any previous adjudication on the same contract or subcontract with its determination (s 13.7(1)).
- The copy to the Authorized Nominating Authority is electronic and on the same day (O. Reg. 264/25 s 20); 'same day' is the only timing, so no window is recorded.
Ask the Authority to appoint a registry adjudicator if the agreed adjudicator has not consented within 4 days after the notice of adjudication
s 13.9(2)-(6); O. Reg. 264/25 s 21, 22 · 4 days · no penalty stated
- Binds the party who gave the notice (s 13.9(4)), and also applies as soon as there is no prospect of agreeing an adjudicator (O. Reg. 264/25 s 22).
- The Authority appoints within 7 days after the request (s 13.9(5)).
- A private adjudicator needs a written agreement signed by the parties and the adjudicator with a fee of at least CAD 1,000 an hour (O. Reg. 264/25 s 21).
- A contract term naming an adjudicator is of no force or effect (s 13.9(3)).
Give the adjudicator the notice, and the adjudicator and the other party the contract and every document relied on, within 5 days after the adjudicator agrees or is appointed
s 13.11; O. Reg. 264/25 s 24 · 5 days · no penalty stated
- Binds the party who gave the notice of adjudication.
- The adjudicator's 30 days run from receiving these documents (s 13.13(1)).
- The Act states no consequence for lateness.
Respond in writing to a notice of adjudication by the day the adjudicator specifies, copied to the adjudicator and every other party the same day
s 13.11.1; O. Reg. 264/25 s 25 · none set · no penalty stated
- Responding is optional (s 13.11.1 says a party 'may').
- The adjudicator sets the day (O. Reg. 264/25 s 25(3)); neither the Act nor the regulation states a day count, so no window is recorded.
- An objection to the adjudicator's jurisdiction must be made when the party first makes submissions (s 13.12.1).
Receive the adjudicator's written determination within 30 days after the adjudicator receives the documents
s 13.13(1)-(6), 13.17.1; O. Reg. 264/25 s 30, 32 · 30 days · a breach of contract
- Extendable before expiry by up to 14 days on the adjudicator's request with the parties' written consent, or by any period the parties agree in writing with the adjudicator's consent (s 13.13(2)); a party who gave a notice of non-payment on the matter must pass on notice of the extension (s 13.13(3), (4)).
- A determination made late is of no force or effect (s 13.13(5)), and the referring party may give a fresh notice of adjudication (O. Reg. 264/25 s 32).
- The adjudicator sends an electronic copy, then a certified copy within 7 days (O. Reg. 264/25 s 30), and may correct errors within 5 days after communicating it (s 13.17.1).
Pay any amount an adjudicator's determination requires within 15 days after it is communicated
s 13.15, 13.19(1)-(6), 13.20 · 15 days · a breach of contract
- 15 days from 1 January 2026 (2024, c. 20, Sched. 4, s. 23); the Act said 10 days before then.
- The determination binds until a court, an arbitration or a written agreement decides the matter (s 13.15).
- An unpaid amount carries interest (s 13.19(3)), and the unpaid contractor or subcontractor may suspend work until paid the amount, interest and the reasonable costs of suspending, and is then owed the reasonable costs of resuming (s 13.19(5), (6)).
- A certified copy may be filed with the court and enforced as its order within 2 years, and the filing party must notify the other within 10 days of filing (s 13.20).
File any motion for leave to seek judicial review of a determination within 35 days after it is communicated
s 13.12.1, 13.18(1)-(7) · 35 days · the claim is barred
- Leave of the Divisional Court is required, with proof of service (s 13.18(1), (2)).
- A determination can be set aside only on the grounds in s 13.18(5), and on a ground that could have been raised as a jurisdictional objection in the adjudication only if failing to object was justified (s 13.18(5.1), 13.12.1).
- An application does not stay the determination unless the court orders (s 13.18(7)), so the 15 day payment still runs.
Refer the owner's non-payment to adjudication within 21 days after giving a subcontractor a notice of non-payment that undertakes to do so
s 6.5(5)(a)(iii), 6.6(6)(a)(iii) · 21 days · no penalty stated
- The undertaking is a required part of a Form 1.2 or Form 1.4 notice (a Form 1.4 needs none where the chain broke at the owner).
- The Act states no consequence for failing to refer within the 21 days.
Where a dispute comes from
The matters that can be adjudicated include any dispute in a notice of non-payment under the prompt payment rules, and payment of holdback.
What this page is, and is not
It is the section text this library holds for Ontario's Construction Act, R.S.O. 1990, c. C.30 (Ontario), the Occupational Health and Safety Act, R.S.O. 1990, c. O.1 (Ontario) and Construction Projects, O. Reg. 213/91 (Ontario), with the window and the consequence. It is not legal advice, and it is not a substitute for reading the Acts, the regulations and the contract you signed.
Demiton does not yet track Ontario projects. These pages set out the duties; the product does not run these checks on an Ontario job today.
No library of law is complete, and Demiton never says this one is. An obligation the library does not hold, and you did not add, is not protected. You can add your own to any job.