Moisture in a rented apartment can often lead to disputes between landlords and tenants. Each party blames the other for the cause of the moisture. In any case, the tenant who discovers the moisture in the rented apartment reduces the rent payment and claims a reduction; The landlord, who does not want to accept the reduction without taking action, takes his claim to court. When considering whether the tenant is right to reduce the rent or whether the landlord can still demand the withheld rent, the following principle applies:
It is established that the landlord must provide the tenant with an apartment that is free of defects and in a usable condition, and must also maintain it in this condition during the rental period. If damp occurs in the apartment, the landlord is obliged to restore it to proper condition and is responsible for doing so, unless the tenant is responsible for the defect and its occurrence.
In cases of moisture damage or mold growth, landlords often accuse tenants of being solely responsible for the defect, claiming that they do not heat and ventilate properly, which leads to moisture-related damage. Tenants regularly defend themselves by pointing out that they heat and ventilate normally and that the moisture is due to a construction defect, such as leaky masonry or insufficient thermal insulation.
Disputes often arise between landlords and tenants over alleged or actual defects in the rented apartment. The tenant then reduces the rent payment and the landlord may have to take legal action to enforce their claim if they do not want to accept the reduction without taking action.
The question of causality can usually only be clarified by an expert. But what if even the expert cannot clearly determine the cause of the defect? Who wins the lawsuit then depends crucially on the burden of proof.
First, the landlord must prove that the moisture damage is not due to a construction defect. If they are unable to do so, the landlord will lose the case for rent reduction if the cause is otherwise unclear. However, if they can prove that the damage is not due to a construction defect, it is then up to the tenant to prove that they are not responsible for the defect either. The tenant can name suitable witnesses who can confirm that the tenant heats and ventilates regularly and appropriately, or prove through expert opinions that the damage is not attributable to faulty ventilation.If it is then established that the tenant is not to blame, their rent reduction is justified on the merits. However, if the tenant fails to provide exculpatory evidence, they lose the case and must pay the previously reduced rent.
In summary: The landlord is responsible for any damage that they cannot prove was caused by the tenant. However, if the landlord can prove that there is no construction defect in the case of moisture damage, the burden of proof is reversed and the tenant must now prove that they are heating and ventilating the property properly.
However, the courts recognize that, in exceptional cases, even if the tenant's ventilation behavior is objectively incorrect, the landlord may be liable for the resulting moisture damage. This applies if the landlord was obliged to inform the tenant of any special circumstances that require ventilation practices that deviate from the norm or a change in ventilation practices. In the case of an old building, for example, the tenant must be prepared for the fact that the rented property may not meet today's technical standards, although even in this case, the tenant cannot be expected to take overly costly ventilation measures (e.g., LG Lüneburg, Ref.: 6 S 70/00). However, the landlord must inform the tenant of the need to change their ventilation habits, especially if they retrofit the rented premises with insulated glass windows (e.g., LG Gießen, Ref.: 1 S 63/00, LG Berlin, Ref.: 64 S 320/99). The consequence of such retrofitting is often that the exterior wallswalls—and no longer the windows, as was previously the case—have the poorest thermal insulation, which can lead to increased moisture and mold growth on the walls unless the rooms are ventilated more frequently than before.
The statements represent initial information that was current for the law applicable in Germany at the time of initial publication. The legal situation may have changed since then. Furthermore, the information provided cannot replace individual advice on a specific matter. Please contact us for this purpose.