A property can appear perfectly healthy on the day of the visit while concealing a serious natural risk: land subject to undeclared clay shrinkage-swelling (RGA), concealed history of flooding or location in a regulated zone kept silent. When a seller voluntarily withholds this information, the buyer is not deprived. The Civil Code offers several avenues of action to restore the balance of the transaction.
These remedies, which are still little known, are based on proof of lack of information: exchanges with the seller, ERP, town planning certificate, risk prevention plans, post-purchase expertise or testimonials from neighbors. They are also linked to the obligation of advice of the notary and the real estate agent. As Pierre Lemarchand, co-manager of the Agence l’Adresse de Saint-Gilles-Croix-de-Vie, recalls: “Today, information on climate risks is an integral part of our advisory duty.»
Cancel the sale or renegotiate the price due to hidden defects
Rehibitory action remains the main tool in the event of a hidden risk. It may lead to the pure and simple cancellation of the sale or to a reduction in the price proportional to the defect. To be admissible, the buyer must demonstrate that the risk existed before the transaction and was not reported. Undeclared flood claims, land classified as an RGA zone or membership of a PPRL not mentioned are common reasons. “Properties located within the perimeter of a PPRL require particular vigilance” warns Pierre Lemarchand.
Responsibility of the notary and the agent: a reinforced duty of information
If the seller has hidden a risk, the professionals who supervised the transaction can also be blamed. The notary must verify the completeness of the ERP, while the real estate agent must provide this information upstream. “We have the obligation to transmit the ERP as well as the georisk information to the buyers before signing the compromise», recalls Pierre Lemarchand. In the PPRL zone, “the seller must in particular have an altimeter survey carried out», an element that can influence the value of the property and the work to be planned. “Depending on the results, certain buyers may be forced to undertake compliance work, with direct consequences on sales times or the value of the property.»
Additional remedies: rescision for injury in extreme cases
Rarer but possible, rescision for injury allows the price to be revised if the buyer has paid an amount that is clearly disproportionate in view of a hidden major risk. This action requires demonstrating a difference of at least seven-twelfths with the real value of the property. It requires extensive expertise and often occurs in addition to other remedies. In a market where climate impacts are becoming structuring, “our role of expertise and support is central to anticipating these impacts, securing the transaction and providing clear information to both sellers and buyers,”concludes Pierre Lemarchand.









