There was a case a while back in British Columbia that involved a house the buyers ended up not really wanting. In Cardwell v. Perthen, the buyers found after purchasing their home that there was shoddy workmanship, leaks, deterioration of structural components and mould. They chose not to get a home inspection at the time they bought, but the court determined that they had the right to obtain a home inspection and that their choice not to do so should not shift the obligation over to the seller.
In BC, as in Ontario, it is the buyer’s obligation to determine whether there is anything wrong with a house before purchase; it is not the seller’s duty to disclose anything that is what is called patent, or discoverable. If you, or a qualified home inspector, could have discovered that there was mould, or mice, or a rusted furnace, the seller is not responsible for compensating you even if you chose not to get a home inspection, unless the seller actually prevented you from getting a home inspection.
In Ontario, truly, the buyer must beware.