Questione giuridica chiave
Whether the rent-default termination under Art. 257d CO was valid despite the tenant's set-off defense based on damages from defects in the leased premises.
Decisione estratta
The notice was valid because the asserted damage claim was contested and not eligible to block rent default termination in these circumstances.
Motivazione estratta
A tenant may in principle raise set-off, but where the counterclaim is a disputed damages claim arising from defects in the premises, the law provides the specific remedy of rent deposit rather than unilateral withholding or set-off; the debt therefore remained unpaid within the warning period.