Its owners had bought it, with a parking space, for €615,000 in 2011 and sold it on for €710,000 in 2016. The couple took the former owners to court, arguing that the sellers had deliberately hidden a situation no buyer could reasonably have overlooked. A Paris court found in their favour in 2021, the Paris Court of Appeal confirmed the decision in July 2024, and on 28th May 2026 the Cour de cassation rejected the sellers’ final appeal. The sellers were ordered to pay €106,500 — 15% of the sale price — to reflect how much less the flat was worth because of the neighbour. A seller must disclose anything likely to weigh materially on a property’s value.