When the Fence Wins: Supreme Court Confirms Municipal Parkland Can Be Lost Through Adverse Possession

Kosicki v. Toronto (City), 2025 SCC 28

In a landmark case, the Supreme Court of Canada has ruled that municipal parkland can be acquired through adverse possession where statutory requirements are met. The Court rejected arguments that judges should create common law immunities for such lands, holding that only the legislature can exempt categories of public land from adverse possession. This decision has important implications for title searches, due diligence, and risk assessment when dealing with properties adjacent to municipal parks.

Background

In 2017, Pawel Kosicki and Megan Munro purchased a residential property in Toronto backing onto Étienne Brûlé Park. They later discovered that the City of Toronto held title to a portion of their fenced backyard—land that had been separated from public access by a fence erected sometime between 1958 and 1971. When the City refused to sell the disputed land based on its policy against disposing of parkland, the homeowners sought a declaration of possessory title under the Real Property Limitations Act, R.S.O. 1990, c. L.15 (“RPLA”).

The application judge and Court of Appeal (with one dissent) both dismissed the claim, holding that a “public benefit test” at common law prevented adverse possession of municipal parkland. The Supreme Court reversed.

The Supreme Court’s Ruling

Justice O’Bonsawin, writing for a five-judge majority, allowed the appeal and declared the homeowners to be the rightful owners of the disputed land. The Court’s reasoning centered on four key principles:

1. The RPLA Governs Adverse Possession Claims

The RPLA provides that no person may bring an action to recover land more than 10 years after dispossession (s. 4), and that title is extinguished at the end of this limitation period (s. 15). The Court confirmed that these provisions apply broadly to “any person” and “any land” without distinguishing between public and private ownership.

It was undisputed that the homeowners satisfied the traditional requirements for adverse possession: their possession was open, notorious, peaceful, adverse, exclusive, actual, and continuous for the requisite 10-year period. The City’s title was therefore extinguished over 40 years ago.

2. Section 16 Lists Specific Exemptions—Municipal Parkland Is Not Among Them

Section 16 of the RPLA exempts certain categories of public land from adverse possession:

• Waste or vacant Crown land
• Road allowances (surveyed and laid out)
• Public highways where freehold is vested in the Crown or a municipality

The Court emphasized that municipal parkland is conspicuously absent from this list. Applying the principle of statutory interpretation expressio unius est exclusio alterius (“to express one thing is to exclude another”), the Court found that the legislature’s specific enumeration of protected lands creates a strong inference that other lands—including municipal parkland—were not intended to be exempt.

3. Legislative History Shows Deliberate Choices

The Court reviewed the legislative evolution of adverse possession law in Ontario, noting that the legislature has repeatedly turned its attention to this area:

• 1922: The legislature exempted road allowances and highways from adverse possession, while expressly preserving possessory rights acquired before June 13, 1922
• Land Titles Act: Section 51(1) prospectively eliminated adverse possession for registered land, but s. 51(2) preserved matured possessory claims
• 2021 amendments: The legislature exempted provincial parkland and certain other public lands from adverse possession (through amendments to the Public Lands Act and Provincial Parks and Conservation Reserves Act, 2006), again preserving matured claims

Throughout this legislative history, the Court observed, the legislature consistently preserved acquired possessory title while prospectively protecting certain categories of public land. Notably, despite these repeated interventions, the legislature never exempted municipal parkland.

4. Courts Cannot Create New Exemptions Contrary to Legislative Intent

The Court held that recognizing a common law immunity for municipal parkland would improperly interfere with the legislative scheme. The Court of Appeal’s “public benefit test”—which would require municipalities to waive rights or acknowledge/acquiesce to private use—was effectively an absolute bar because it required permission to adversely possess, which contradicts the very nature of adverse possession.

The Court emphasized: “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.” Creating retroactive exceptions would defeat the RPLA’s purpose as a statute of repose and undermine the legislature’s clear policy choices.

The Result

The Supreme Court declared Kosicki and Munro to be the fee simple owners of the disputed land and directed the land registrar to amend the title accordingly.

Note on the Dissent: Four judges dissented (Justices Karakatsanis, Martin, Kasirer and Jamal), finding that common law recognizes a presumptive shield for municipal parkland designated for public benefit. However, the majority’s reasoning establishes binding precedent on the interaction between statutory limitation periods and judicial creation of common law immunities for public land.

Practical Implications for Transactional Lawyers

Title Searches and Due Diligence

1. Adjacent municipal lands: Exercise heightened caution when properties abut municipal parkland, conservation areas, or green spaces
2. Historical fencing: Investigate the history of boundary fences, particularly those potentially enclosing municipal land
3. Survey plans: Review historical survey plans deposited with land registrars for evidence of boundary discrepancies
4. Pre-2001 claims: Pay special attention to properties where fences or structures potentially enclosing municipal land predate the Land Titles Act conversion

Risk Assessment

1. Limitation periods: The 10-year limitation period under the RPLA may have run before municipal authorities discovered encroachments
2. Matured claims: Section 51(2) of the Land Titles Act preserves possessory claims that matured before land title conversion
3. No special municipal protections: Unlike some jurisdictions (e.g., Alberta), Ontario does not statutorily exempt all municipal land from adverse possession

Client Advice

1. Purchasers: Obtain title insurance and consider specific endorsements for boundary disputes involving municipal lands
2. Vendors: Disclose any knowledge of property lines encroaching on municipal land, even if long-standing
3. Property tax assessments: The decision notes that property taxes were paid on the disputed land—clients may have claims for reimbursement if taxes were paid on municipal land by mistake

Legislative Watch

The majority emphasized that policy questions about adverse possession’s continued utility should be addressed by the legislature. Ontario may yet enact legislation specifically addressing municipal parkland, as other provinces have done. Practitioners should monitor for potential legislative responses to this decision.

Conclusion

The Supreme Court’s decision in Kosicki provides important clarity: Ontario’s statutory scheme for adverse possession applies to municipal parkland just as it does to private property, absent express legislative exemption. The Court firmly rejected judicial creation of common law immunities that would contradict legislative choices, emphasizing that policy reforms in this area are the province of the legislature, not the courts.

For transactional lawyers, the key message is clear—municipal ownership does not automatically protect parkland from adverse possession claims where the statutory requirements have been met and matured before land title conversion.

For queries involving properties with potential boundary issues concerning municipal lands, consider consulting with a real estate litigator specializing in adverse possession claims.