Ontario Adjudication in 2026: What Owners Should Do When a Notice Arrives

Ontario owners should no longer think of adjudication as a narrow payment process that disappears when the work is complete. As of January 1, 2026, the adjudication regime gives parties specific deadlines to start adjudication, permits a broader range of disputes to be brought under it, and makes early procedural decisions more important.

Before turning to the practical implications for owners, it helps to see the process as a whole. The flowchart below provides a high-level overview of the first steps in adjudication under Ontario’s 2026 regime.

Adjudication may now arrive after the project appears to be over

One of the most important changes is timing. Under the amended Construction Act, an adjudication in respect of a contract generally cannot be commenced more than 90 days after the contract is completed, abandoned, or terminated, unless the parties agree otherwise. That gives more certainty than the old regime, but it also means owners should not assume that close-out ends adjudication exposure.

For owners, that shifts the contract close-out process. Project files now need to remain adjudication-ready for 90 days after termination, abandonment, or completion. If a dispute is still open, the contract record, payment history, change documentation, and schedule record should remain accessible and organized.

Adjudication may now reach beyond a simple payment dispute

Owners should also stop treating adjudication as only an unpaid-invoice mechanism. The scope of adjudicable matters has now been expanded by O. Reg. 264/25. In addition to traditional payment disputes, the regulation captures issues such as:

• the scope of work required under the contract;
• a request for a change in the contract price; and
• a request for an extension of time,

where determination of those issues is reasonably necessary to resolve the adjudication.

That matters because an adjudication notice may now affect more than just accounts payable. It may require owners to respond quickly on change history, contract interpretation, delay events, and project administration decisions. In practice, weak project records may become as dangerous as a weak legal position.

Owners need to make threshold decisions immediately

The 2026 changes also place more pressure on the owner's first response.

The amended regime now expressly addresses jurisdictional objections. If a party says the adjudicator lacks jurisdiction, the objection must be raised when that party first makes submissions to the adjudicator, unless the adjudicator extends the time. If the objection is that the adjudicator has exceeded jurisdiction during the adjudication, it must be raised as soon as the matter arises.

The practical takeaway is simple: if the owner believes the adjudication is out of time, outside the prescribed scope, or otherwise defective, that analysis should happen immediately. Waiting can narrow the owner's options.

Consolidation is now a bigger issue on troubled projects

The amended regime also expands consolidation. Where there are overlapping issues, any party may now require consolidation in prescribed circumstances, with the agreement of the adjudicators of the separate adjudications. The regime also requires disclosure of prior relevant adjudication determinations under the same contract, so the adjudicator has the full picture.

For owners, that means a disputed project may no longer involve one isolated issue. Separate fights about payment, changes, and delay may become interconnected and additional parties might be involved Since project records can be massive, an owner who tracks only individual invoices may miss connections among related disputes and fail to raise the consolidation argument when it’s needed. Owners should therefore track adjudications at the project level, not just at the invoice level.

A private adjudicator may offer flexibility, but at a price

The amended regime also allows parties to agree to a private adjudicator if the prescribed conditions are met. That adjudicator must still be a certified ODACC adjudicator. One of the prescribed conditions is economic: the adjudicator’s fee must be at least $1,000 per hour.

That may be worthwhile on a large or technical dispute where both sides want a particular decision-maker. But it also means owners should not agree to that route casually. In many cases, the cost and speed trade-off should be considered before the notice of adjudication ever arrives.

Practical steps for owners

Owners should consider building a simple adjudication protocol. At a minimum, that protocol should require the team to:

• confirm the contract and the relevant trigger dates;
• check whether the dispute falls within the adjudication scope;
• assess any timing or jurisdiction objection immediately;
• pull the core record right away, including the contract, amendments, payment notices, change documents, schedule materials, and key correspondence;
• check whether there are already related adjudications on the same project; and
• decide quickly whether there is any realistic prospect of agreeing on an adjudicator.

Key takeaways

• Do not assume adjudication risk ends when the project ends.
• Check the contract and both the Construction Act and the O. Reg. 264/25 before deciding whether a dispute belongs in adjudication.
• Treat the first response as a strategic step, not an administrative one.
• Track related adjudications across the project.

Ontario's 2026 adjudication changes are ultimately about speed, scope, and early decision-making. For owners, the practical lesson is not complicated: when a notice arrives, the response plan should already be in place.

If you have questions about how Ontario's updated adjudication regime affects your project administration, contract drafting, or dispute response strategy, our team at Construct Legal can help.

This article is not legal advice and is provided for informational purposes only.