The application must be dismissed for

Practical application:

Because the landlord and the previous owner both knew of the encroachment yet remained inactive for years, a court would likely treat this as tacit acceptance, barring demolition. He should gather all evidence of when the wall was built and any past correspondence. Instead of litigation, he should propose a boundary agreement or seek compensation from the neighbour to regularise the situation.

Practical application:

Even though the buyers only just discovered the trespass, the previous owners' prolonged silence may be considered tacit acceptance, binding the new owners. They should immediately contact the notaire to verify if any easement was omitted from the deed. They should also engage the neighbour to negotiate a boundary adjustment or a formal servitude, as a demolition claim is unlikely to succeed and could harm neighbourly relations.

Practical application:

The Cour de cassation ruling suggests that the syndicat des copropriétaires (co-owners' association) may have tacitly accepted the encroachment by its prolonged inaction, even without a formal vote. The new co-owner should review past AGM minutes for any discussions or decisions. Rather than seeking demolition, they could propose that the balcony owner pays an annual indemnity to the co-ownership and obtains a proper convention d'occupation (occupation agreement) to regularise the situation.