Hidden defect (salainen virhe)

A hidden defect (salainen virhe), also called a latent defect, means a fault that neither party knew about and could not reasonably have detected at the time of the deal. The key point is that the seller’s liability exists even if the seller acted carefully and gave all the information honestly. The measure is whether the property differs significantly in quality from what can reasonably be expected of a comparable property, taking into account the purchase price and other circumstances.

In a real-property sale, hidden defects are governed by the Land Code (maakaari), and in the sale of a share-based apartment (osakehuoneisto) by the Housing Transactions Act (asuntokauppalaki). The threshold is high: small or ordinary wear is not enough, the fault must be significant in relation to the property’s age, price, and condition. Typical examples are moisture or mould damage hidden inside a wall structure, or a drainage system that does not work, which becomes apparent only after the deal.

If you suspect a hidden defect, act quickly. A defect notice (reklamaatio) must be made within a reasonable time from when the defect was noticed or should have been noticed, and it is not worth delaying. A condition inspection (kuntotarkastus) done before the deal reduces the risk and records visible faults, but it does not remove the seller’s liability for a hidden defect. Establish the cause and extent of the defect with documentation, because any price reduction or cancellation of the deal is decided on the significance you can demonstrate.