Executive Summary: Key Legal and Evidentiary Issues

• Whether Mylenn Joannette committed a fault by pruning a co-owned (mitoyenne) cedar hedge without the prior consent of her neighbour, Linda Labossière.
• Under article 985 of the Civil Code of Québec, a neighbour bothered by encroaching branches must demand that the owner cut them and seek court intervention if refused, rather than take justice into their own hands.
• Solidary liability of Simon Desgroseilliers turned on evidence that he actively participated in and consented to the pruning, engaging article 1480 of the Civil Code.
• Uncontradicted expert evidence from arboricultural consultant Mathieu Sauvé established that the damaged hedge section had suffered irreversible damage and required replacement, valued at $19,205.72.
• Most counterclaim heads (lawyer's fees, lost income, arborist consultation, privacy-screen costs) failed for lack of proof or as non-compensable inherent litigation inconveniences.
• Photographic and testimonial evidence of Labossière repeatedly spying on Joannette through the hedge supported an award of moral damages for abnormal neighbourhood annoyances under article 976.

Facts of the case

Linda Labossière and Simon Desgroseilliers own adjoining properties in the district of Beauharnois, separated along the disputed portion by a cedar hedge that the parties acknowledged, at a pre-trial management conference, to be mitoyenne (co-owned). Mylenn Joannette has lived on the Desgroseilliers property as a tenant since 2019. In June 2023, while Labossière was away from her residence, Joannette — together with Desgroseilliers and a third party not involved in the proceedings — significantly pruned the hedge's branches from the Desgroseilliers side, over a height of about six and a half feet. Upon her return, Labossière noticed the hedge appeared sparser. In August 2023 she retained arboricultural consultant Mathieu Sauvé to assess the replacement value of the damaged section, and in November 2023 obtained a quote from Extermination Denis Brisson inc. (Centre de jardin Brisson) setting the restoration price at $29,538.23. By letter delivered no later than November 17, 2023, she put the defendants in default to pay $23,620.45, and in this action claimed $15,000, the small claims jurisdictional ceiling. The defendants counterclaimed for $7,100, covering court fees ($430), lawyer's fees ($170), lost income ($960), an arborist consultation ($120), the cost of installing a privacy screen ($2,950), and moral damages for harassment ($2,500). The hearing proceeded in the absence of Desgroseilliers, although he had been duly summoned.

Legal provisions and property rules at issue

Because the hedge was mitoyenne — a sui generis form of forced undivided co-ownership — neither co-owner could destroy or modify it without the other's consent; the will of the party wishing to preserve the hedge as it stands prevails over that of the party wishing to alter it. Article 985 of the Civil Code of Québec provides the lawful route for a neighbour seriously inconvenienced by encroaching branches or roots: demand that the neighbour cut them and, upon refusal, compel them to do so through the courts. Article 1480 makes persons who jointly participate in a wrongful act causing injury solidarily liable when it cannot be determined which of them actually caused it. On the counterclaim, article 976 governs neighbourhood annoyances, requiring neighbours to tolerate only the normal inconveniences that do not exceed the limits of tolerance owed to one another. Joannette's own letter to Labossière acknowledged the core problem, stating that her error had been to assume she could trim her side without consulting her neighbour beforehand.

The court's reasoning and analysis

Judge Philippe de Grandmont of the Court of Québec, Small Claims Division, held that Joannette committed a fault by unilaterally cutting the co-owned hedge without notice to or consent from Labossière, and that her good faith belief that the work posed no danger to the hedge's survival changed nothing. Relying on prior case law applying article 985, the court stressed that a party inconvenienced by an overgrown hedge must denounce the problem, send a formal demand, and if necessary apply to the courts — not resort to self-help. Sauvé's expert report concluded the hedge section had to be replaced because the opening created had caused irreversible damage to the plants, and the defendants offered no contradicting evidence. Desgroseilliers was found solidarily liable because the evidence, including the defendants' own letter of November 17, 2023 confirming they carried out the complete cutting of the branches with the owners' authorization, showed his active participation and consent. On quantum, Sauvé's replacement-value assessment totalled $19,205.72; although no explanation justified purchasing 300 cm replacement plants where the Brisson garden centre considered 250 cm plants sufficient, this was inconsequential since the replacement cost would reach $15,000 even with smaller plants. On the counterclaim, the court rejected the claims for lawyer's fees, lost income, the arborist consultation (unproven), and the privacy screen, reasoning that the defendants could not recover expenses incurred to remedy the consequences of their own fault. It did, however, find Labossière's conduct wrongful in turn: she admitted observing Joannette through the hedge, and a photograph combined with Joannette's testimony — describing roughly ten incidents per summer season in 2023, 2024 and 2025 — made the repetitive character of this spying plausible. The court held that intentionally going to the property line to spy on neighbours exceeds tolerable neighbour behaviour, though it did not retain Joannette's medical evidence, which failed to establish a causal link between Labossière's conduct and her symptoms.

Ruling and outcome

Labossière emerged as the principally successful party: the court granted her claim in full and solidarily ordered Joannette and Desgroseilliers to pay her $15,000, with interest at the annual rate of 5% plus the additional indemnity under article 1619 of the Civil Code from November 17, 2023, together with legal costs including Sauvé's expert fees of $344.93. The counterclaim succeeded only in part and only for Joannette, given Desgroseilliers' absence at the hearing: Labossière was ordered to pay Joannette $2,500 in moral damages for the loss of privacy caused by her visual intrusions, with interest at 5% plus the additional indemnity from January 15, 2024, and legal costs in the defendants' favour. The court ordered set-off (compensation) between the sums the parties owe each other, leaving a net award in Labossière's favour before interest and costs.