The Council of State (Decision 1616/2025) ruled that unauthorised constructions in common areas of multi-owner buildings cannot be regularised without the unanimous consent of all co-owners when no condominium regulation exists. The Court held that enclosing or altering common spaces, such as the pilotis, affects the substance of co-ownership rights and cannot be validated through majority approval or by relying on Law 4178/2013. The decision reinforces long-standing principles of condominium law and confirms that interventions altering the purpose or use of common property require full co-owner agreement.