Practical regulations
Managing the right to build upward
The right to build upward, known in Italian law as diritto di sopraelevazione, allows the owner of the top floor, or the exclusive owner of the roof terrace, to add new floors or structures above an existing building. Article 1127 of the Italian Civil Code governs this right and balances it against two precise limits: the building's structural conditions must allow it, and the new construction must not harm the building's architectural appearance. Whoever builds upward must also pay compensation to the other co-owners, proportional to the value the occupied area loses as a supporting structure. For a property manager, the practical work centers on checking documentation, coordinating with the assembly, and correctly updating ownership shares, tasks that a platform like AmministraPro helps keep organized over time.
Who holds the right and under what conditions
Article 1127 of the Civil Code assigns the right to build upward to the owner of the building's top floor. If the roof terrace belongs in exclusive ownership to a different co-owner, or if a right of surface has been established in favor of a third party, the right to build upward belongs to whoever holds that title, not automatically to whoever occupies the top floor.
The right does not depend on prior consent from other co-owners: it is a legal faculty tied to ownership, not a concession granted by the assembly. This means the assembly cannot refuse the addition on grounds of mere convenience, but it can and should verify that the objective limits set by the law are respected.
The two limits under article 1127: structure and appearance
The first limit concerns the building's structural conditions: if they do not allow it, the addition cannot proceed unless reinforcement works are carried out at the expense of the party seeking to build upward. A licensed structural engineer should assess loads, foundations, and the existing load-bearing structure before work begins.
The second limit is the building's architectural appearance, which the new construction must not harm. This is not an absolute ban on changing the exterior, but a duty of harmony with the lines, materials, and style of the existing building. Courts evaluate case by case whether the new volume noticeably alters the building's overall appearance as seen from outside.
A further, less known limit concerns a significant reduction of light and air to the floors below beyond a considerable extent, or a significant decrease in the commercial value of the existing units.
Compensation owed to the other co-owners
Whoever builds upward must pay the other co-owners compensation, calculated by dividing the value of the area occupied by the new structure by the number of floors, including the new one being built. The resulting sum is then distributed among the co-owners of the floor directly below, excluding those who hold no title to the common area or structure used as the base for the addition.
The compensation offsets the loss, for the other co-owners, of any future possibility of using that area or its covering function. It does not require a complex expert appraisal, but rather a reasoned estimate of the occupied area's value at the time of the addition, often assigned to a private surveyor or agreed amicably between the parties.
The role of the assembly and the property manager
Even though building upward is an individual right, the property manager plays a practical role: verifying that the project does not alter common parts such as the roof, stairwell, or shared systems without authorization, informing the assembly of the work notified by the interested owner, and updating the ownership share tables once the work is completed, since the new unit contributes to common expenses based on its acquired value.
It is good practice for the manager to request copies of the technical documentation, including structural reports and building permits, and for the assembly to formally acknowledge the work and the revision of the ownership tables. Keeping organized records of notices, minutes, and technical documents, ideally through dedicated management software, helps avoid later disputes over expense allocation.
Frequently asked questions
Can the owner of the top floor build upward without the other co-owners' consent?
Yes, the right to build upward under article 1127 of the Italian Civil Code is a legal faculty tied to ownership of the top floor or the exclusive roof terrace, not a concession the assembly can refuse at will. The assembly can, however, verify compliance with the legal limits, namely the building's structural conditions and its architectural appearance, and request the technical documentation before work starts.
How is the compensation owed to other co-owners for building upward calculated?
The compensation is calculated by dividing the value of the area occupied by the new construction by the total number of floors in the building, including the new one being added. The resulting figure is then distributed among the co-owners of the floor immediately below the addition, excluding anyone with no title to the common part used as the base of the new construction.
What happens if building upward harms the building's architectural appearance?
If the new construction noticeably harms the building's architectural appearance, article 1127 of the Civil Code prohibits it: this is one of the two explicit limits of the rule, together with structural conditions. In case of dispute, whether the appearance has actually been compromised is decided by a court, based on technical expert opinion and an overall assessment of the architectural context.
Does the property manager need to update ownership shares after an addition is built?
Yes, once the addition is complete the new unit acquires its own value and must be included in the ownership share tables, with a consequent revision of how common expenses are split among all co-owners. The property manager is responsible for initiating this update, gathering the technical documentation and presenting it to the assembly, and tools like AmministraPro help keep documents, resolutions, and updated tables in a single organized record.
Who is entitled to compensation if the roof terrace is not owned exclusively by the top floor?
If the roof terrace, or the right to build upward, belongs exclusively to a co-owner other than the top floor occupant, or to a third party holding a right of surface, that party holds the right to build upward and must pay compensation to the other co-owners under the same criteria set out in article 1127, regardless of who actually lives on the top habitable floor.
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