Key legal question
Whether the alleged neighbor nuisances constituted defects of the leased premises.
Extracted holding
Even if such nuisances can in principle amount to defects, the tenant could not rely on the defect remedies here because the conflict was partly attributable to his own conduct.
Extracted reasoning
Neighbor or third-party nuisances exceeding tolerance may be defects, but a defect imputable to the tenant cannot justify remedies under Arts. 259a-h CO. The lower courts found reciprocal provocations and a breach of mutual consideration under Art. 257f para. 2 CO.