GC4I team, structural engineering firm in Montreal
A crack that opens after the purchase, a sagging floor, a leak that was never mentioned: when a structural defect appears after the sale, the question of a latent defect arises. The law decides; the engineer provides the technical facts.
This article describes the engineer’s role. It does not replace the advice of a lawyer, who remains the person to consult about your rights, your deadlines and the strategy to follow.
The four conditions, and what the engineer has to say about them
The seller’s warranty of quality is set out in article 1726 of the Civil Code of Québec. For a defect to be recognized as a latent defect, four conditions are generally examined. The engineer decides none of them, but their assessment informs three of them.
| Condition | What it means | The engineer’s contribution |
|---|---|---|
| Severity | The defect makes the property unfit for its intended use or greatly reduces its usefulness. | Assessment of the effect on the structure and of the extent of the corrective work. |
| Pre-existence | The defect existed before the sale. | Technical clues: age of a crack, corrosion, deformations, construction details. |
| Hidden nature | A prudent and diligent buyer could not have detected it. | Description of what was visible, or not, at the time of the sale. |
| Lack of knowledge | The buyer was unaware of the defect. | A matter of proving the facts, not of technical expertise. |
The expert’s mission before the court
Article 22 of the Code of Civil Procedure states that the expert’s mission is to enlighten the court, and that this mission takes precedence over the parties’ interests, even when one of the parties retained the expert. The expert attaches to the report a statement regarding the performance of their mission.
The parties can also give the assignment to a joint expert. When several experts are involved, the court may ask them to meet to pin down the points on which they disagree.
What the engineer actually does
The steps of a latent defect assessment
- Written mandate: the question asked, the documents received, the limits of the work.
- Visit: observations, measurements, photos and, with the agreement of the parties concerned, exploratory openings.
- Analysis: mechanism of the defect, probable causes, signs that it pre-existed.
- Report: findings, method, analysis, conclusions, extent of corrective work and limitations.
- Testimony: presenting the report before the court, if the case goes that far.
What not to do
Repairing before giving notice of the defect and letting the seller see it, throwing away removed elements, or opening a wall without photographing and documenting it: all of these can weaken the evidence.
Deadlines to know
The buyer must give the seller written notice of the defect within a reasonable time after discovering it, and give the seller the opportunity to see the problem. The deadline to take legal action is generally three years from discovery. Your lawyer will tell you what applies to your situation, including whether the contract contains a warranty exclusion clause.
FAQ
Does a pre-purchase inspection protect the buyer?
It is part of the prudence expected of a buyer, but it is generally visual and can’t reveal everything. What it found, or should have found, can weigh in assessing whether a defect was hidden.
Can the seller attend the assessment?
It’s often advisable: letting the seller see the problem is one of the expected steps. The arrangements are decided with your lawyers.
What is a counter-assessment?
It’s the review, by another engineer, of a file that has already been assessed. It checks the findings and the reasoning, and can confirm or qualify the conclusions.
Can the engineer estimate the cost of corrective work?
They describe the extent of the work needed; depending on the assignment, an estimate can be attached or requested from an estimator or contractors.
A defect discovered after the purchase?
Before any repairs, have the situation documented. Describe the problem and the context: we’ll send you a written service proposal for the assessment.
Scope of this guide. This content is general in nature. It does not replace a site visit, an engineer’s opinion on a specific building or legal advice.
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