September 3, 2019


Tree removals, boundary trees and nuisance


Rob Kennaley In many, if not most, municipalities in Canada, a tree removal by-law or legislation dictates an approval is obtained before a tree of a certain caliper can be removed. Often, whether or not the approval will be granted will depend on a number of factors, including whether or not the tree is damaged, will threaten persons or property, is in the way of necessary infrastructure changes or will be replaced with suitable replacement trees capable of providing similar or better shade, wildlife habitat and/or CO2 contributions.   

Things change, however, when we are talking about a boundary tree, which is situated on a property line between two adjoining properties. In that case, receiving prior municipal or regulatory approval may not be sufficient to remove a tree, in particular a “boundary tree.” Disagreement over removal of a boundary tree can often be contentious and lead to legal action.  

In Allen v MacDougall, 2019 ONSC 1939, the Ontario Superior Court of Justice considered the removal of a boundary maple tree to accommodate the expansion of an owner’s home. The tree was healthy, had been on the property for 50 to 60 years and was in existence prior to the arrival of the owners. The owners had obtained relevant municipal permits to remove the tree. Their neighbours objected on the basis that they were part owners of the tree and as such, the owners could not unilaterally decide to remove it. In support of this notion, counsel for the neighbours went so far as to state “that no matter how unreasonable it may seem not to let your neighbours take your property, you can refuse to do so even if the neighbours really need it.”  

The owners (in an application for an order allowing them to demolish the tree) argued that they should be entitled to remove the tree based on the law of ‘nuisance.’ They argued that the tree was a nuisance because it was in the way of their planned, and necessary, expansion. They relied on a number of cases, including a Supreme Court of Canada case that recognized, at common law, “an owner would clearly have a right to claim for nuisance against roots, branches, etc., growing on his land from a tree located on his neighbour’s land.” The owners argued that “this principle should not change just because the tree straddles the boundary line between the two properties.”

The court, however, stated that “If your own use of your property constitutes a nuisance, the neighbour may be in a position to interfere with that use” and that “(t)he law of nuisance seeks to balance the competing rights of owners — one neighbour to do what he wants and the right of the other neighbour not to be interfered with.” It went on to hold that contemporary environmental considerations had decreased the orders to remove trees on the basis that branches etc. breached a neighbor’s property, unless the tree has caused damage to an abutting property or is physically impeding access to the neighbour’s land. In this case, there was no evidence the tree had caused any damage to the owner’s house or to any other structure on the property. The court also noted that the tree had not been a nuisance for the first 18 years the owners had lived on the property and had only became a nuisance when the owners decided to add an addition to their home.

Ultimately the court applied the test annunciated by the Supreme Court of Canada in Antrim Truck Centre Ltd. v. Ontario [2013] 1 S.C.R. 594 which states, “for there to be a nuisance, there must be an interference with a property owner’s use and enjoyment that is both substantial and unreasonable.” Substantial interference is, according to the Supreme Court, something that materially interferes with “ordinary comfort as defined according to the standards held by those of plain and sober tastes.” In this case, the Ontario Court relied upon the unrefuted expert report of the neighbour’s arborist, which had determined that the maple tree provided significant environmental, economic and social benefits to both parties. On this basis the Court found the destruction of the maple tree was not trivial and therefore did not meet the “substantial” portion of the test.

As regards the second part of the test, the court must consider reasonableness from a competing property rights point of view and ask whether the conduct of the person claiming nuisance is reasonable given the fact that they have a neighbour. In making its determination the court must examine the nature and character of the property. In this instance the court again relied upon the neighbour’s expert report, which found much of the north side of the backyard, where the owners had planned to build the addition, was within a tree protection zone while the south side of the backyard was not. The court stated the owners did not consider the reasonable alternative of changing their design to avoid the destruction of the maple tree. The court held that the onus was on the owners to demonstrate the maple tree must be destroyed and as a result required the owners to demonstrate that there were no reasonable alternatives available.  

This case gives us some insight into how a court will deal with disputes over boundary trees and into the law of nuisance, which can raise its head in a number of construction law contexts.

Robert Kennaley practices construction law in Toronto and Simcoe, Ont. He speaks and writes on construction law issues and can be reached for comment at 416-700-4142 or at This material is for information purposes and is not intended to provide legal advice. Readers who have concerns about any particular circumstance are encouraged to seek independent legal advice in that regard.