The September 2026 counter-tariffs put duties of up to 50 per cent on the materials that form the spine of most budgets. Which side of the border a duty is collected on decides whose cost it becomes.
It is Canada's counter-tariffs on US-origin material, not US tariffs on Canadian exports, that raise an Ontario contractor's input costs.
The published price indices predate the September 2026 measures, so current escalation allowances are almost certainly understated on steel-heavy scope.
The exposure is concentrated in a small number of packages — structural steel, metal deck, studs, drywall, formwork — not spread evenly across a budget.
A soft residential market will not deliver cheaper labour; trade availability and material cost are moving in opposite directions.
Most commentary points at the wrong clause. Under CCDC 2 the tariff provision is GC 10.1, it adjusts the price automatically, and it runs in both directions — but claims are won and lost on quantum and notice.
A price adjustment provision is only as good as the evidence needed to operate it. The drafting choices that look neutral at tender are the ones that decide whether the clause ever pays out.
Since April 2026 bidders on Ontario public infrastructure attest to where their materials come from. Tariffs push sourcing one way and the directives push it the other, and the gap between them is contractual.
An extension of time is not granted because the project is late. It is granted because a specific event, for which the other party bears risk, moved the critical path — and the record proves it.
Prompt payment and interim adjudication changed the tempo of construction disputes in Ontario. The analysis has to be ready when the clock starts, not after.
Once the time is established, the cost has to be built from the accounting record. Formula-based head office claims are where most quantum submissions lose credibility.
Most delay analyses fail at the as-built stage. Rebuilding what actually happened, from daily records rather than from updated programmes, is the work that decides the outcome.
