Kernrechtsfrage
Whether the rent increase justified by local and neighborhood customary rents was proven under Art. 269a lit. a OR.
Extrahierter Entscheid
The landlord had not shown a sufficiently broad set of comparable dwellings and therefore had not proven local and neighborhood customary rent.
Extrahierte Begründung
Customary rent requires a sufficiently widespread practice from which a rule can be derived; at least five comparable objects are generally needed. The landlord bears the burden of proof, and the submitted comparisons were insufficient and partly no longer verifiable.