An unfortunate and all too common type of legal case involves the allegation of failure to disclose a latent defect during a sales transaction. This concern occurs especially so in realty transaction matters.
Sellers of homes often come under attack from the buyer following a sale whereas the buyer alleges that the seller failed to advise of a defect (eg. leaky basement, asbestos, etc.). Unfortunately, in these cases as in most legal matters, the burden of proof upon the Plaintiff (the suing buyer) is difficult to overcome especially the burden to prove that the seller had knowledge of the defect. As was shown in the case of Crone v. Kilmer, 2013 CanLII 55833, much more than simply a "gut feeling" that the seller was aware of a defect is needed for the Plaintiff to successfully prove a case.
Generally, the doctrine of caveat emptor (buyer beware) applies to the sale of items such as homes and it is necessary for the buyer to inspect for defects (usually via a qualified home inspector). However, where a home contains a defect that is dangerous or otherwise makes the home uninhabitable, and this defect is known to the seller, as per the precedent established in McGrath v. MacLean, 1979 CanLII 1691, the seller is required to provide disclosure of the defect.
Additionally, the doctrine of caveat emptor fails to apply in situations where the seller has actively taken steps to conceal a defect from discovery by buyer prior to, and at the time of, sale. The caveat emptor doctrine also fails to apply where a material misrepresentation was made by the seller where 'but for' the misrepresentation the buyer would have avoided dealings with the seller and avoided the transaction completely. This rule applies even in the circumstances where an object was sold on an As Is basis as was decided in Mautner v. Metcalf, 2008 CanLII 3969 where it was stated that:
(a) the vendor is not bound to call attention to patent defects; the rule is 'caveat emptor';
(b) where there is active concealment of an otherwise patent defect, the general rule of ‘caveat emptor will not apply’;
(c) if a vendor actively conceals a latent defect, the rule of caveat emptor no longer applies and the purchaser is entitled, at their option, to ask for a rescission of the contract or compensation for damages;
(d) a vendor may be liable to a purchaser with respect to premises which are not new if he knows of a latent defect which renders the premises unfit for habitation. But, as is pointed out in the lecture above referred to, in such a case it is incumbent upon the purchaser to establish that the latent defect was known to the vendor, or that the circumstances were such that it could be said that the vendor was guilty of concealment or a reckless disregard of the truth or falsity of any representations made by him; and
(e) where there are no "clues" and no reasonable means of testing for defects that liability for actively concealing defects, whether patent or latent, actively not disclosing latent defects, or fraudulently misrepresenting facts relating to latent defects, remains with the seller, subject to the requirement with respect to active concealment or active non-disclosure that the same constitute a fraud on the purchaser the same as a fraudulent misrepresentation would.
General Damages (inconvenience compensation)
In addition to the cost of correcting the defect, or diminuition of value if the defect is unremediable or unreasonably remediable, courts now recognize that where inconvenience and annoyances as well as other distress occurs, an award of general damages may be available, even without medical evidence. As stated by Justice Harper in Kelly, et al v. Pires, et al, 2015 ONSC 2871:
 They did not call any medical evidence to support their claim that they suffered from the stressful situation in which they lived. They called no supporting evidence to their claim that the living circumstances caused a strain on their marriage.
 I have no doubt that the plaintiffs’ living circumstances created substantial stress and anxiety in their lives. Their living conditions were unsafe for their children. The children had to stay at their grandparent’s home for a period of time. The family had to live in very small quarters upstairs while the remediation was taking place. Ms. Kelly was reasonably in constant fear that her children might open the door and be subjected to a serious fall as the deck had to be removed in order to put a proper drainage system in. the parties lost the use and enjoyment of their4 property for an extended period. However, without any substantiating evidence or professional opinion, quantifying the extent of their stress and anxiety for the purpose of determining appropriate damages is difficult.