## 4 Conclusions  
In this paper, the seismic and energy rehabilitation of an abandoned RC tobacco factory in Cervinara, in the district of Avellino (Italy), is proposed by designing steel exoskeletons and by installing a photovoltaic plant on the roofs of the building. In situ tests and visual inspections allowed to understand all of the geometrical and mechanical features of the building structural elements used to obtain a FEM model through the SAP2000 software, which allowed to carry out pushover analysis on the building. While the factory showed a good performance in the longitudinal (x) direction with satisfactory safety indices, in the transverse (y) direction, the absence of an appropriate number of seismic-resistant frames reduced the seismic performances, with safety indices less than one. The detected seismic deficiencies led to the design of the optimal seismic intervention to reach an improvement of the seismic features. Steel exoskeletons allowed to improve the global behavior of the building, without neglecting architectural quality, sustainability, and environmental issues. In the weakest building direction (Y-direction), these systems allowed to reach increases in terms of strength and displacements, in order to satisfy the required seismic demand, to attain the complete seismic retrofitting of the structure. In particular, exoskeletons allowed to reach an increase of seismic safety of about 30% by acting only on the building lateral stiffness. Therefore, the significant increase of the safety indices, with values greater than one, decidedly improved the seismic behavior of the building. This satisfactory result testified the validity of this intervention from a seismic viewpoint.  
On the other hand, from an energy viewpoint, a photovoltaic plant was designed using high-efficiency panels installed on the wide roof area. The annual production of photovoltaic plant per square meter was compared that of schools and offices, variable in the range from 60 kWh/m\({}^{2}\) to 170 kWh/m\({}^{2}\), to understand if the plant can provide the entire building's energy requirement. The performed analyses showed that the energy consumed by the retrofitted building is between 20% and 60% lower than that of school and office buildings. This means that, using these new energy generation systems, the photovoltaic plant allowed to generate an amount of energy able to satisfy the entire building requirements.  
As a conclusion, the proposed study showed the validity of exoskeletons as efficient systems to improve both seismic features of RC buildings and values of Italian industrial heritage, which should be preserved and restored since they represent irreplaceable testaments to the industrial archaeology widespread on the Italian territory.  
Conceptualization, A.F.; methodology, A.F.; software, Y.M.; validation, A.F.; former analysis, Y.M.; investigation, A.F. and Y.M.; resources, A.F. and Y.M.; data curation, A.F. and Y.M.; writing--original draft preparation, Y.M.; writing--review and editing, A.F.; visualization, A.F. and Y.M.; supervision, A.F.; project administration, A.F. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The work was developed in the framework of the WP2 task \"Cartis\" of the Italian DPC-ReLUIS 2019-2021 research project, which is gratefully acknowledged.  
The authors declare no conflict of interest.