Kernrechtsfrage
Whether the landlord had to bring the validation action within 30 days after failed conciliation to preserve the rent increase.
Extrahierter Entscheid
Yes. Because the conciliation authority only recorded failure, the party persisting in its substantive claim had to seize the court within 30 days; here that was the landlord.
Extrahierte Begründung
Under Art. 274f para. 1 CO, the 'party that persists in its claim' must sue within 30 days. In a rent-increase dispute, the claim originates from the landlord, even if the tenant initiated conciliation. Failing to act in time counts as waiver.