From Trilogy To Doctrine: The Growing Strength Of Legal Nonconforming Rights In Ontario

• Published date: 16 June 2025
• Subject Matter: Real Estate and Construction, Construction & Planning, Real Estate
• Law Firm: Gowling WLG
• Author: Crystal McConkey, Jacob Polowin and Michael Polowin

Since the publication of the "Legal Nonconforming Rights Trilogy in Ontario" on May 14, 2021, Ontario's jurisprudence around legally nonconforming uses and buildings has continued to develop with remarkable clarity and confidence.

Two new decisions'927 Wellington Street Inc. v. Ottawa and Roca Investment Holdings Inc. v. Ottawa'demonstrate not just the endurance of the Trilogy's (TDL Group, Brougham, and Fraser) principles, but their expansion into a broader and more structured body of doctrine that is reshaping land use planning across the province.

The rise of a doctrinal framework

The Trilogy laid down essential pillars: municipalities cannot extinguish legally nonconforming rights through planning instruments, and property owners retain the ability to evolve or intensify these uses, subject only to the test of undue adverse impacts.¹ We note that Fraser appeared to extend the doctrine of "acquired rights" to limit the regulatory ability of Conservation Authorities, but that is a matter still in evolution.

The two recent decisions extend and reinforce these principles in distinct but complementary ways'Wellington by affirming the adaptability of use, and Roca by confirming the resilience of use despite vacancy and disrepair.

Case update #1: 927 Wellington Street Inc. v. Ottawa ' Evolution without extinction

In 927 Wellington, the Tribunal considered whether a long-standing automobile service station use could evolve into an equipment rental business...