Question juridique clé
Whether the demolition of the overbuilding gave rise to expropriation compensation
Solution extraite
No compensation was owed because the structure, built without a right to build over the stream and in bad faith, belonged to the state-owned stream parcel under accession.
Motifs extraits
The cooperative had never been granted an overbuilding right and could not acquire one by prescription; art. 674 ZGB did not help because the structure was not a mere encroachment into the airspace and the cooperative could not be considered good faith after the 1971 refusal.