Questão jurídica principal
Whether the tenants were entitled to a rent reduction based on the property's net yield
Decisão extraída
The challenged rent reduction was upheld; the landlords failed to show that the admissible net yield justified denying the reduction.
Fundamentação extraída
The cantonal court could depart from the expert report because it relied on estimates and contested construction-cost figures rather than proven effective costs. The landlords did not establish higher effective architect/promotion fees or mortgage interest charges.