Alberta is a buyer-beware province, with real limits. The line runs between what a buyer could find and what only you know.
Alberta operates on caveat emptor, buyer beware. The buyer is expected to inspect and satisfy themselves about what they are buying, which is why a home inspection matters here.
Two things override all of that. You cannot actively conceal a defect — painting over it, panelling across it, hiding it for a showing. And you cannot lie in answer to a direct question: answering falsely is a different legal problem than not volunteering.
Alberta does not use the mandatory province-wide seller disclosure form some other provinces require, though a property condition statement may be used in a given transaction. That puts more weight on what is said, and written, around the deal.
Worth advice rather than a guess: repaired basement water, a former grow operation or remediation history, structural repairs, unpermitted work, a pending condominium special assessment, and anything you have claimed on insurance. Your REALTOR® also has disclosure obligations under Alberta’s real estate rules and cannot conceal a known material latent defect on your behalf.
Disclosing costs you a conversation and possibly a price adjustment. Not disclosing costs you a lawsuit after you have spent the money. Sellers regret the second constantly and the first almost never.
This page is orientation, not legal advice, and disclosure is one of the few parts of selling where the specifics decide the answer. If you are weighing whether something must be disclosed, ask a real estate lawyer before the home is listed, not after an offer arrives. Related: the Real Property Report and compliance stamp, where unpermitted structures usually surface.