Public Land, Private Boundaries: What the Supreme Court’s Kosicki Decision Means for Ontario Property Owners - Adverse possession Ontario
- Sahil Bhardwaj
- 3 days ago
- 4 min read
By Sahil Bhardwaj – Bhardwaj Law Professional Corporation
The Supreme Court of Canada’s 2025 decision in Kosicki v. Toronto (City) has quietly changed the landscape of Ontario property law. For decades, most people assumed that public land, especially municipal parkland or land taken by expropriation, could never be lost to a private neighbour claiming ownership through adverse possession.
Kosicki changes that assumption.
The Court made one thing clear:
Unless Ontario’s Legislature has explicitly protected certain categories of public land, the usual adverse possession rules apply, even to municipal parkland.
That means some public lands may now be vulnerable to private claims if they have been fenced in, used privately, or neglected for long periods of time.
This is a major development affecting homeowners, municipalities, conservation authorities, developers, and anyone whose property borders public land.
In Ontario, the Real Property Limitations Act (RPLA) sets the rules for adverse possession.
Under the RPLA:
If someone occupies land openly, continuously, and exclusively for 10 years
And the true owner does nothing to stop them
The true owner’s rights can be extinguished, and title can transfer to the possessor.
For decades, most experts believed public land, especially parkland, was immune. Kosicki says otherwise.
The City of Toronto expropriated land in 1958 for conservation/park purposes.
A fence was built, and a neighbouring homeowner began using part of that land as their private backyard.
This private use continued for decades.
When the City eventually tried to reclaim the land, the homeowner (Mr. Kosicki) claimed possessory title.
Both the trial court and the Court of Appeal rejected the claim, saying municipal parkland was “implicitly protected” based on public policy.
But the Supreme Court disagreed.
Public Land Is Not Automatically Protected
The Supreme Court ruled that:
✔ The RPLA is a complete code for adverse possession Ontario
✔ Only property categories listed in the statute are immune
✔ Municipal parkland is not listed, and courts cannot invent new exceptions
✔ Public land can be lost through adverse possession unless the Legislature has said otherwise
In plain language:
If the statute doesn’t protect it, the courts can’t protect it.
The Court rejected the “public benefit test” previously used by Ontario courts and reaffirmed that judges must apply the legislation as written, not expand it based on policy concerns.
If your property borders:
a park
a ravine
a laneway
a utility corridor
conservation land
or any municipal strip of land
…then long-term occupation of “unused” or fenced-off public land could have legal consequences.
Homeowners may now:
Have stronger arguments for possessory title over fenced or enclosed strips of public land
Be able to legally claim land that municipalities ignored for 10+ years
Face boundary changes if municipalities “wake up” after years of inaction
Municipalities now:
Must actively inspect and maintain public lands
Must demonstrate clear acts of ownership
Can no longer rely on assumptions of public immunity to adverse possession
Risk losing land acquired decades ago through expropriation or dedication if it has been neglected
A major issue in Kosicki was whether expropriated land, taken for public purposes, should automatically remain public forever.
The Supreme Court said no:
The Expropriations Act gives the government title
But it does not provide ongoing immunity from the RPLA
Once expropriated, the land is treated like any other land unless legislation says otherwise
This means expropriated land left unmanaged for years may be vulnerable.
Kosicki requires a more proactive approach. Public authorities should:
Conduct regular inspections of boundary areas
Maintain or re-install signage, gates, or fencing
Issue notices of entry
Remove private encroachments early
Ensure public access is clear
Document management activity
Consider converting eligible land to Land Titles Absolute
Because once the 10-year limitation clock runs out, the land may be lost for good.
If you believe you’ve been using part of a neighbouring public parcel for a long time—especially if there is fencing, landscaping, or exclusive use—you should get legal advice immediately.
You may have a claim for:
Possessory title
Boundary clarification
Injunctions to prevent removal
Negotiated regularization or conveyance
If you are unsure whether your use qualifies, we can advise.
Kosicki reinforces a fundamental principle:
Courts do not rewrite legislation, if an exemption is not in the statute, it does not exist.
That means:
Future protection for municipal land must come from the Legislature, not judges
There may be lobbying or amendments to section 16 of the RPLA
Public expectations about the security of public land may shift
Private rights may be stronger than previously assumed in certain scenarios
The Kosicki decision is a significant clarification of Ontario’s property regime:
It confirms that adverse possession still applies to many categories of public land
It narrows judicial discretion
It increases responsibility for public land management
It opens the door for new private claims
And it may lead to legislative reform
For property owners, municipalities, conservation authorities, and planners, the message is clear:
If you have questions about boundaries, adverse possession, encroachments, or a dispute involving municipal or public land, we can help you navigate your options and protect your interests.
Contact Bhardwaj Law Professional Corporation
Visit www.bblaw.ca to schedule a consultation.
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