Tenants' Set-off Claim for Improvement Value Against Rent Arrears Rejected Despite Contractual Waiver

In a provisional enforcement ruling dispute, the court addressed whether tenants could offset claims for rent arrears with counterclaims for the increased value of their improvements, despite a contractual waiver of compensation. The court upheld the lower court's decision, reasoning that under federal jurisprudence, the waiver of compensation for significant value enhancement by a tenant, as stipulated in Article 260a of the Code of Obligations (OR), is permissible because the provision is dispositive, not mandatory. Therefore, such a contractual agreement takes precedence over claims arising from unjust enrichment (Art. 62 ff. OR) or property law provisions concerning accession (Art. 672 Civil Code), meaning the tenants could not successfully assert their counterclaims through set-off.