Tenant's Appeal on Cost Allocation After Full Rejection of Rent Reduction Claim

The appellate court reviewed a decision where the lower court dismissed a tenant's action for rent reduction and related claims entirely, awarding all procedural costs to the landlord, leading the tenant to appeal, arguing for shared costs based on success in some subsidiary points of the claim. The court upheld the cost allocation, reasoning that under the principle of success (§ 119 Abs. 1 ZPO), the overall outcome of the process dictates cost liability, and it is not determined by the numerical ratio of success or failure across individual disputed aspects of the case, finding no abuse of discretion in assigning all costs to the party whose primary claim was wholly rejected.