SCC rules 5-4 in favour of Toronto homeowners’ adverse possession claim against municipal parkland

Law360 Canada (September 19, 2025, 5:46 PM EDT) -- In a far-reaching adverse possession judgment that rejects a judge-made immunity for municipal parkland facing matured possessory claims in Ontario, the Supreme Court of Canada has ruled 5-4 that two Toronto homeowners own a piece of adjoining municipal parkland that was fenced into their backyard decades ago by the home’s previous owner.

On Sept. 19, 2025, Justice Michelle O’Bonsawin allowed the appeal of Pawel Kosicki and Megan Munro, whose home, acquired in 2017, backs onto a laneway owned by the City of Toronto, which is beside Étienne Brûlé Park, a large municipal park that stretches along the Humber River: Kosicki v. Toronto (City), 2025 SCC 28.

The couple’s property also encompasses a trapezoid-shaped piece of the parkland — which disputed land makes up a considerable portion of the appellants’ backyard, and which the home’s previous owner fenced in with a chain link fence sometime between 1958 and 1971 — thereby preventing the public’s access.

The city didn’t learn that the disputed land was enclosed by the fence until 2021 when Kosicki inquired about purchasing it from the city, but the city refused based on its long-standing policy not to convey parkland.

Kosicki and Munro responded by applying unsuccessfully to Ontario’s courts for a declaration that Kosicki had become the owner of the disputed lands by reason of adverse possession.

The Ontario Superior Court judge below found that a “public benefit” test for adverse possession of public land has been articulated in some lower court decisions. Under that test, an adverse possession claim will fail if the land (1) was acquired by the city for the use or benefit of the public, and (2) was in fact used by the public. The application judge went on to conclude that the public benefit test was not satisfied because the municipality failed to demonstrate that the disputed land had ever been used by the public before the chain link fence was erected.

Nevertheless, she dismissed the homeowners’ application on the basis that the disputed land was originally acquired for an important public interest purpose and, as a matter of public policy, a private landowner may not fence off public lands and exclude the public and then succeed in a claim for adverse possession.

The Ontario Court of Appeal’s majority subsequently upheld the application judge’s rejection of the homeowners’ request for a declaration of ownership, but reframed the public benefit test, removing the requirement that the municipality demonstrate actual use. The majority stated that adverse possession claims will not succeed where the land was purchased by, or dedicated to, the municipality for the use or benefit of the public, and the municipality has not waived its presumptive rights over the property, or acknowledged or acquiesced to its use by a private landowner.

In reaching their conclusion, Ontario Court of Appeal Justices Lorne Sossin and James MacPherson (Brown J.A. dissenting) found that Ontario’s Real Property Limitations Act (RPLA) did not preclude the further development of the common law in relation to lands not explicitly addressed in s. 16 of the RPLA, such as municipal parkland. The majority held that the common law refinements made to the public benefit test did not contravene s. 16 as they did not provide an absolute immunity from possessory claims for municipal parkland, but created a rebuttable presumption that such land is unavailable for adverse possession.

(Under s. 16 of the RPLA, the Ontario legislature has exempted certain public lands from the application of the RPLA for over a century, including waste or vacant Crown land, road allowances and public highways. New exceptions for additional categories of exempted public land have been enacted in related statutes since the last amendments to the RPLA, but they do not mention municipal parkland.)

In allowing the homeowners’ appeal, Justice O’Bonsawin, backed by Chief Justice Richard Wagner and Justices Suzanne Côté, Malcolm Rowe and Mary Moreau, held that the couple became the owners of the land because they met the criteria for adverse possession and there was no rule specifically protecting municipal parkland.

“Under the applicable statutory rules, the City’s title to the land was extinguished over four decades ago,” Justice O’Bonsawin wrote. “To accept the City’s argument would be to interfere with the appellants’ matured possessory claim and disregard the applicable statutory scheme.”

Justice O’Bonsawin said that the RPLA, which extinguishes both the title and the right of the paper titleholder to recover the land 10 years after dispossession, governs the dispute.

“The legislature has exempted certain public lands from the application of the RPLA for over a century,” she noted. “New exceptions for additional categories of public land have been enacted in related statutes since the last amendments to the RPLA. Although these new exceptions grant explicit protection to provincial parkland from the application of the RPLA, they do not mention municipal parkland. Moreover, despite prospectively abolishing the possibility of acquiring possessory title for land registered under the Land Titles Act, R.S.O. 1990, c. L.5, the legislature has preserved matured possessory claims.”

Justice O’Bonsawin said the preservation of acquired possessory title is consistent with the RPLA’s purpose as a statute of repose. “In this statutory context, to recognize a new common law exception in addition to the exceptions the legislature has set out in s. 16, which would serve to retroactively deprive a claimant of acquired possessory title, would defeat the legislature’s intent.”

The majority noted that since 2001, the provincial government has protected parkland in Ontario through a land title registration system that does not allow for new adverse possession. In the case at bar, however, the criteria for adverse possession were met for the period required by the RPLA before the registration system started, i.e., there was: actual possession of the land; an intention to exclude the true owner; and effective exclusion of the true owner. Therefore, the right to become an owner through adverse possession was preserved, and the appellants could be declared owners of the strip of land.

In arguing that the appeal should be dismissed, in his dissenting judgment endorsed by Justices Andromache Karakatsanis, Sheilah Martin and Mahmud Jamal, Justice Nicholas Kasirer ruled that the disputed land was not acquired by adverse possession as an extension of the appellants’ backyard. The position most consistent with both the jurisprudence and the legislative context is that the public benefit test at common law remains operative alongside the RPLA, Justice Kasirer held.

Although the applicants met the requirement of constructive notice for adverse possession, they failed to meet the more stringent test that, at the relevant time, the municipality acquiesced to private use of the public land, Justice Kasirer reasoned.

“The appellants’ pre-existing fence — and the fences abutting on parkland across the City — may preclude public use of the land, but does not change the park’s vocation to the benefit of the public, nor does it give rise to a settled expectation that the City acquiesced to the appellants’ possession,” he wrote.

The dissenters said the disputed land’s public character, reinforced by its designation as green space, remains undisturbed. “This understanding of the public benefit presumption against adverse possession of a municipal parkland visits no unfairness on the applicants in the instant case,” Justice Kasirer said. “The applicants cannot say that they have a valid adverse claim based on their exclusive possession when that exclusivity is a consequence of the very fence that excluded the public from use of land designated for community benefit. Because the principle explained by the majority of the Court of Appeal was not new law but simply a plainer articulation of a longstanding common law rule, the applicants cannot say that their claim had crystallized as a mature right to title before a notional change in the law.”

Sarah Turney of Toronto’s Fasken Martineau DuMoulin LLP, who with Daniel Richer and Jasmeen Kabuli represented the successful appellants, said, “This case settles the law after years of uncertainty, due in part to a series of Ontario court decisions that indicated that parkland ought to be treated differently from other types of land under the Real Property Limitations Act.”

“Those decisions led to the development of a ‘public benefit test’ that made it difficult, and in some cases impossible, to establish a possessory title over municipal parkland,” she explained. “The Kosicki decision clarifies the law and confirms that it is the intent of the legislature, and the effect of the RPLA, to preserve matured claims of adverse possession on municipal parkland.”

Turney added that beyond the decision’s implications of particular interest for real estate and municipal lawyers, “the decision provides important guidance for any case where the common law meets a statutory scheme, as outlined in the following passage from the ruling: ‘That the legislature has not completely ousted the common law does not permit courts to supplement a statute in a manner that is inconsistent with legislative intent.’”

Ray Mikkola of Pallett Valo LLP in Mississauga, Ont., a senior commercial real estate lawyer who acts for a number of municipalities but who is not connected with the case, said the Supreme Court’s judgment is of note.

“Wow,” he remarked. “The Supreme Court of Canada provided clear direction as to the law respecting adverse possession, guidance on how a statutory scheme impacts on the development of the common law, and the protection of established interests in real property.”

He pointed out that the top court’s majority also criticized the so-called “public benefit test” and the Ontario Court of Appeal’s endorsement of the lower court’s modification of the test to not require actual possession of parkland as a key component of the test.

“This decision will undoubtedly be cited in the future, even in a non-real-property context, as it contains a treasure trove of important legal findings across a variety of legal applications,” Mikkola predicted.

He suggested that, in the decision’s wake, there appears to be little scope left for the continued application of the public benefit test, as promulgated by the Court of Appeal below.

“The majority took aim at what it called the ‘unsettled foundations’ of the test,” Mikkola said. “It was not necessary for the majority to delve deeper into other questions respecting the application of the public benefit test beyond parkland — such as whether the test could be applied to adverse possession claims against a municipally owned parking lot, storm water management pond, and other municipally owned property also held for the general benefit of the public. The majority may have been concerned about a floodgates-type of argument in this regard respecting other municipally owned property.”

Asked whether the court’s ruling will lead to amendments to the RPLA to cover municipally owned parkland, Mikkola answered “perhaps.”

“But the expansion of the Land Titles Act in the province decades ago — under which claims are possible only if they crystallized prior to conversion to Land Titles — to accommodate electronic titles means that there should be fewer instances of adverse possession claims against parkland over time.”

“Would such amendment provide immunity to all municipal lands, as Alberta has done?” he queried.

“Would they grandfather crystallized claims?” he added. “Presumably, all land held by a municipality is held for the benefit of the public.”

Counsel for the respondent City of Toronto, and the counsel for the intervener attorneys general of Ontario and British Columbia, the City of Ottawa and Advocates for the Rule of Law, had not responded to Law360 Canada’s requests for comment by press time.

“We are still reviewing the decision and … unable to provide comment,” replied Philip Huynh, city solicitor and counsel for the intervener City of Surrey, B.C.

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