Kernrechtsfrage
Whether ancillary costs were validly and sufficiently specially agreed to be borne by the tenant under the commercial lease.
Extrahierter Entscheid
No. The contract did not specify which ancillary costs were charged to the tenant, and monthly advances alone did not establish the required special agreement.
Extrahierte Begründung
Art. 257a(2) CO requires a clear and precise special agreement identifying the ancillary-cost items. The lease only mentioned a monthly advance and final settlement, without listing the costs. Payment of advances cannot replace the missing agreement.