The Supreme Court of Canada declared a Toronto couple owners of a disputed part of their backyard on September 19, 2025, ruling that municipal parkland status could not defeat an otherwise established historical claim to the land through adverse possession.
In Kosicki v. Toronto (City), 2025 SCC 28, a five-judge majority rejected a judge-made protection for municipal parkland that the lower courts had used to deny the claim. The Court declared Pawel Kosicki and Megan Munro the owners of the parcel, directed the land registrar to amend the register and awarded them costs throughout the proceedings.
The result depended on possession that had matured decades earlier. The disputed land entered Ontario’s land titles system in October 2001, protecting it from new adverse possession arising afterward. The judgment concerned the survival of an older claim, not the creation of a new right to take over registered parkland by putting up a fence.
A backyard boundary dating to at least 1971
Kosicki and Munro bought their home in 2017. Their backyard backed onto a municipal laneway separating the homes from Étienne Brûlé Park along the Humber River. A roughly trapezoidal portion inside their backyard fence was registered to the City of Toronto.
The larger tract, including the disputed parcel, had been expropriated by a conservation authority in 1958 and conveyed to the municipality in 1971. A survey prepared for that conveyance showed the backyard fence. It had been erected sometime between 1958 and 1971 and had excluded the public from the disputed land since at least 1971.
After discovering the ownership issue in 2021, the couple asked to buy the land. The City refused under its policy discouraging sales of land in its Green Space System. It said the parcel could be used to widen access to the park and add signs if recovered. The couple instead sought a declaration of ownership based on the long history of exclusive possession.
Toronto conceded that the ordinary adverse possession requirements were met. Its position was that land designated for public park purposes deserved additional protection. The application judge rejected the couple’s claim on public-policy grounds, and the Ontario Court of Appeal upheld that result using a test that presumed municipal land dedicated to public benefit was protected unless the municipality waived its rights or acknowledged or acquiesced in the private use.
Statutory choices controlled the outcome
Writing for the majority, Justice Michelle O’Bonsawin said that additional common law protection conflicted with Ontario’s legislation. Under the Real Property Limitations Act, qualifying dispossession for 10 years extinguishes the paper owner’s right and title to the land. The required possession must be open and notorious, adverse, exclusive, peaceful, actual and continuous, with an intention to exclude the owner and effective exclusion.
The legislation expressly protects certain public lands, including specified Crown lands, road allowances and public highways. Other statutes address additional categories such as provincial parkland. The majority concluded that municipal parkland was not covered by an applicable exception in this case, and courts could not add one inconsistent with the legislature’s choices.
O’Bonsawin did not hold that the common law had no remaining role in adverse possession. Courts still define and apply concepts such as dispossession. But that role had to respect the statutory scheme, including its repeated protection of possessory claims that had already matured.
That distinction mattered when the parcel was converted to the land titles system on October 22, 2001. Although registration stopped new possessory claims from developing, the legislation preserved qualifying rights acquired beforehand. The majority held that Toronto’s title had already been extinguished more than four decades before the Supreme Court judgment and could not be revived through a new common law rule.
The majority also questioned the logic of requiring a municipality to consent to the private occupation. Adverse possession involves possession without permission; making consent essential would effectively prevent the doctrine from operating. Whether stronger protection for municipal land would be good policy was a question for the legislature within this statutory setting.
Four judges emphasized the public’s interest
Justice Nicholas Kasirer, joined by Justices Andromache Karakatsanis, Sheilah Martin and Mahmud Jamal, would have dismissed the appeal. They viewed the public-benefit test as a clarification of existing common law that could operate alongside the legislation, rather than a new immunity contradicting it.
The dissent reasoned that land held for a community park differs from privately owned land. Loss of a small parcel could permanently deprive the public of its benefit, while monitoring extensive municipal holdings imposed costs on the community. Parkland should therefore be presumed to remain in public use unless the municipality changed its purpose or knowingly accepted private use.
Kasirer would have allowed compelling evidence of constructive knowledge, rather than insisting on actual knowledge in every case. But he found the 1971 survey insufficient to establish municipal acquiescence. Later surveys and the couple’s property-tax payments could not establish the necessary position before the 2001 registration cutoff.
The majority took the opposite view of the governing law and allowed the couple’s application. Its declaration resolved ownership of the disputed parcel in their favour. The broader significance was the protection of matured possessory claims under Ontario’s statutory scheme, despite the municipality’s designation of the land for park purposes.
