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Selling a Home With an Unpermitted Renovation in Ontario

Past renovation work done without a permit raises real disclosure questions for Ontario sellers. Here's what you're generally expected to tell a buyer.

Real Estate5 min readTSLBy the Treadstone Law team · OntarioUpdated 2026-07
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Key takeaways
  • It's worth separating two situations that get talked about together but aren't the same.
  • Ontario real estate law draws a long-standing distinction between two categories of property problems: - Patent defects — issues a buyer could reasonably discover through their own…
  • None of this automatically means a problem exists — plenty of unpermitted work is perfectly sound.

Not every past renovation went through the municipality. A finished basement, a converted garage, a knocked-down wall — plenty of Ontario homes carry work that was never permitted, sometimes done by a previous owner long before the current seller ever bought the place.

That history doesn't automatically stop a sale. But it does raise a genuine question sellers need to think through honestly: what do you actually have to tell a buyer, and what happens if you don't?

Unpermitted Work Is Different From an Open Permit

It's worth separating two situations that get talked about together but aren't the same. An open permit means a permit was pulled and the work was never formally signed off. Unpermitted work means no permit was ever applied for at all, for work that likely needed one. Unpermitted work carries an added layer of uncertainty, since there's no municipal record of the project ever being reviewed in the first place.

What Sellers Are Generally Expected to Disclose

Ontario real estate law draws a long-standing distinction between two categories of property problems:

Unpermitted renovation work sits in a gray area depending on the facts: a cosmetically finished basement that looks fine on a walkthrough may hide unpermitted electrical or structural changes a buyer has no realistic way to spot. If a seller knows about a genuine safety issue tied to that work, staying quiet is a real legal risk, not just a moral one.

Common Situations That Come Up

ScenarioTypical Concern
Finished basement with an added bedroom, no permitEgress window and fire-separation compliance are common sticking points
Secondary or basement apartment created without permitsZoning, fire code, and unit-count compliance for a legal second unit
DIY electrical or plumbing changesSafety compliance and potential insurance implications
Structural changes, such as a removed load-bearing wallWhether the work was engineered and inspected properly at the time

None of this automatically means a problem exists — plenty of unpermitted work is perfectly sound. The issue is that, without a permit and inspection on file, there's no independent confirmation either way.

How This Plays Out in a Sale

Most Ontario resale agreements are negotiated on an arm's-length basis, with the buyer expected to conduct their own due diligence — inspections, permit searches, and so on. A seller isn't generally required to volunteer every fact about a property's history unprompted. But two things change that calculus:

  1. Direct questions. If a buyer or their agent asks specifically about permits or past renovation work, an inaccurate or misleading answer can expose the seller to a misrepresentation claim, separate from any general disclosure duty.
  2. Known safety issues. Where a seller actually knows unpermitted work created a real safety problem, "the buyer should have inspected more carefully" tends not to excuse silence about something the seller was specifically aware of.

Practical Options for Sellers

Frequently asked questions

Can I sell a house "as is" to avoid disclosing unpermitted work?

Marketing a sale as-is doesn't override a seller's obligation to be honest about known latent defects or to avoid actively misrepresenting the property. It shifts more risk onto the buyer for issues they could have discovered themselves, but it isn't a blanket shield.

What if I bought the house with the unpermitted work already there?

You're generally expected to disclose what you actually know, not what a previous owner may have known and never told you. If you're aware of the unpermitted work now, that awareness is what matters going forward.

Will unpermitted work stop the sale from closing?

Not usually on its own. It's more often addressed through negotiation — a price adjustment, a holdback, or an agreement that the buyer proceeds knowing the history. Whether it derails a deal depends on how serious the issue is and how the parties choose to handle it.

Should I just permit the work retroactively before selling?

If there's time before listing, it's often worth exploring with the municipality, since it can remove the uncertainty entirely. Whether retroactive permitting is realistic depends on the scope of the work and whether it can be brought into compliance without significant changes.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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