What is a latent defect and does a seller have to disclose it in Ontario?

A latent defect is a hidden problem with a property that is not discoverable by a reasonable inspection — something concealed or not visible during an ordinary buyer walkthrough. A material latent defect is one that makes the property dangerous to live in, unfit for habitation, or otherwise significantly impairs its use.

In Ontario, sellers have a legal obligation to disclose known material latent defects that meet this threshold. Active concealment of such a defect — for example, covering up a known mould problem or a serious foundation crack — can expose the seller to liability even after closing, and even in an "as is" sale.

However, sellers are generally not required to volunteer information about obvious or patent defects that a buyer could discover on a reasonable inspection. The legal distinction between latent and patent defects matters, and the line is not always clear. This is another reason the home inspection condition is valuable — it converts otherwise hidden risks into visible, reported ones that you can act on before your condition deadline.