Public land, private claims: Reassessing adverse possession after Kosicki v. Toronto (City)

In Kosicki v. Toronto (City), the Supreme Court of Canada confronted a question with sweeping implications for municipal property rights: can private homeowners claim adverse possession (or “squatters’ rights”) over land designated as municipal parkland?

The appellants bought a home in Toronto in 2017, only to discover years later that a portion of their fenced backyard, which had been used openly and continuously for decades, actually belonged to the City of Toronto. The land had been expropriated in 1958 and transferred to the City in 1971, forming part of a tract designated as public green space under the City’s “Green Space System”.

When the City refused to sell the land, citing its policy against disposing of parkland, the homeowners sought possessory title under Ontario’s Real Property Limitations Act (“RPLA”). The application judge acknowledged that the couple met the statutory test for adverse possession but rejected the claim “as a matter of public policy,” reasoning that private citizens should not be allowed to fence off public land and later benefit from it. The Ontario Court of Appeal upheld that decision, reframing what it called a public benefit test that would bar adverse possession over land held for the use or benefit of the public unless the municipality had expressly acquiesced.

The majority opinion

Justice O’Bonsawin, writing for Chief Justice Wagner and Justices Côté, Rowe, and Moreau, allowed the appeal and restored the homeowners’ claim. The majority held that the City’s title had been extinguished over four decades ago. The Court emphasized that Ontario’s legislature had already decided which public lands are immune from adverse possession. Municipal parkland was not one of them. Section 16 of the RPLA contains a “closed list” of exceptions - covering highways, road allowances, and Crown lands, but it does not include parks.

“Recognizing a novel common law immunity for municipal parkland,” O’Bonsawin J. wrote, “cannot be reconciled with the relevant statutory scheme and would defeat the legislature’s intent”. The Court stressed that the RPLA is a statute of repose, meant to bring finality to land claims by extinguishing the rights of paper title holders after ten years of continuous dispossession. To graft a new common law immunity onto this legislative scheme would amount to judicial amendment of the statute, something the Court refused to do.

The majority concluded: “The applicants should be declared the fee simple owners of the disputed land”, reaffirming that the RPLA governs even where the land happens to be municipal parkland.

The dissent

Justice Kasirer, joined by Justices Karakatsanis, Martin, and Jamal JJ, dissented. In their view, the public benefit test remains part of the common law and continues to coexist with the RPLA. They argued that municipal parkland is “presumptively in use by the public and shielded from adverse possession” unless the municipality has changed the land’s vocation or acquiesced to private use.

For the dissent, the doctrine of adverse possession, which is rooted in rewarding productive land use, has “limited resonance when the titled owner of the land is a public entity”. They warned that penalizing cities for failing to patrol their boundaries would impose social and economic costs to the public, including costs to taxpayers. While acknowledging that the appellants’ possession met the technical elements of adverse possession, Kasirer J. insisted that the public’s long-term interest in preserving urban green space outweighed private convenience: “The public would make a more socially valuable use of this land over time…than could any one person”.

The dissent also took issue with the majority’s interpretation of the RPLA, describing it as “a patchwork quilt of disparate enactments” that leaves space for the common law to evolve. In their view, section 16 of the RPLA was not a closed list, and courts retain authority to recognize common law limits on adverse possession of municipal parkland.

Significance

Kosicki v. Toronto (City) marks a decisive victory for Ontario property holders asserting possessory rights over municipal parklands where the test for adverse possession is otherwise satisfied. This decision also represents a significant clarification of the boundary between statutory and common law in property disputes. The majority’s judgment underscores that the RPLA governs adverse possession in Ontario comprehensively and that courts cannot create new exemptions under the guise of public policy. As O’Bonsawin J. observed, "to recognize a new common law exception... would defeat the legislature’s intent."

For municipal governments, the ruling serves as a caution: unless parkland is expressly exempted by statute, long-term encroachments could mature into private ownership.

For property lawyers, the decision reaffirms that legislative clarity is critical in determining the reach of adverse possession. 

The dissent’s eloquent warning about the “social value” of public green space will likely continue to influence debates over the scope of property rights and the balance between private and public interests. But as of now, Kosicki v. Toronto (City) stands as a reaffirmation of legislative supremacy in defining the limits of possession and ownership in Canadian property law.