Water Infiltration from a Terrace in an Italian Condominium: Who Is Liable

Water infiltration from a terrace in an Italian condominium is one of the most frequent disputes in condominium life, because it involves both a technical problem that needs a fast fix and a legal question about who must pay for the repair and compensate any damage. Level terrace, roof deck, walkable balcony: the terminology varies, but the core issue is always the same, namely establishing who is obligated to act and according to what criterion the cost is split among the owners involved.

Where the infiltration comes from

Infiltration from a terrace or roof deck almost always stems from the failure of the waterproofing layer, caused by wear over time, poorly executed work, water buildup from clogged downpipes, or a lack of periodic maintenance. The surface acts as a covering for the unit below, so a defect in the seal quickly translates into dampness, staining, and sometimes structural damage to the rooms on the lower floors. Identifying the exact source of the problem, often through a technician or a company specialized in leak detection, is the first step before any discussion of cost allocation.

The cost allocation criterion under article 1126

When a terrace or roof deck is for the exclusive use of one owner but also functions as a covering for the building below, article 1126 of the Italian Civil Code sets out a cost split for repair or reconstruction in which the owner with exclusive use contributes a proportionally larger share, while the remaining part falls on the owners the deck serves as a covering for, in proportion to the value of their respective units. This criterion reflects the fact that whoever exclusively uses the surface gains an additional benefit beyond its simple covering function, and therefore contributes a larger share of the cost than the other owners.

A terrace shared by all owners

The situation is different when the terrace or roof deck is not for exclusive use but remains a common area available to all owners of the building: in this case, maintenance and repair costs follow the ordinary general ownership share criterion, without the higher share applied to exclusive use. Verifying the nature of the use, exclusive or shared, is therefore an essential preliminary step before applying any cost split.

The condominium's liability as custodian

Beyond splitting repair costs, the question often arises of compensating damage already occurring in the unit below, such as damaged plaster, ruined furniture or mold. The condominium, as custodian of the common areas, can be held liable for damage caused by a structural defect under the general rules on liability for things in custody, unless it proves the damage resulted from an unforeseeable and unavoidable event. Liability often overlaps with that of the individual owner if the damage was worsened by their own conduct, for example by failing to promptly report the problem.

The contribution of case law from the Joint Divisions

Over the years, Italian case law, including rulings from the Joint Divisions of the Court of Cassation, has repeatedly clarified the relationship between the owner with exclusive use of the roof deck or terrace and the condominium, specifying that the maintenance obligation and the cost split under article 1126 do not exclude additional liability of the condominium when the damage arises from a shortfall in the overall management of the building, such as failing to schedule maintenance work that had long been known to be necessary.

The exclusive-use criterion affects how repair costs are split, but it does not in itself exclude the condominium's liability toward owners harmed by the infiltration.

How to proceed in practice

When infiltration appears, the property manager should act quickly to have the cause investigated, convene the assembly to approve urgent action, and formally inform the owner with exclusive use of the terrace of the findings. Prompt action limits the extent of the damage and reduces the risk of broader disputes, while an unjustified delay can be considered a contributing factor to the worsening of the damage itself.

1. Technical assessment of the source of the infiltration
2. Verification of the nature of use, exclusive or shared
3. Assembly resolution for the intervention and the cost split
4. Where relevant, separate handling of compensation for damage to the units below

The role of insurance

Many building block policies cover, with specific limits and deductibles, infiltration damage to the units below, but often exclude the cost of structurally repairing the roof deck or terrace itself, treated as maintenance rather than an accidental event. Reading the policy terms carefully helps the property manager understand what is actually covered and inform owners correctly before an expectation of reimbursement forms that does not match the actual contractual terms.

Managing an infiltration case, from the technical assessment to the resolution and the calculation of the cost split between the exclusive user and those who only benefit from the covering function, requires precise tracking and documentation, an area where dedicated software can help considerably. AmministraPro supports property managers through exactly these steps: the features page describes the tools for managing extraordinary works, while the pricing section lists the plans available for every type of firm.