Traditional buildings are bearers of the values already mentioned in the Introduction, thus, the need to refurbish them cannot be separated from an approach that increases the level of their sustainability. However, this term must be considered in the broadest sense and cannot be associated only with energy saving, as often happens. Therefore, in this research the most peculiar features of the traditional buildings (relationship with the landscape, indoor comfort, structural behavior, etc.) were chosen as the focus of the analysis.
Through the application of the methodology on the Filicudi it was possible to identify the overall quality of the island’s construction. The survey tool developed allowed easy analysis of the results obtained in each category.
For the macro-area Building (Figure 12
), the score totalized by each residential unit is satisfactory. The average value μ is equal to just under 19 out of 20, and therefore, well above the median value. In addition to the data that can be displayed on the diagrams and on the table, it is interesting to note how the scores are distributed in each district. In particular, the Contrada of Valdichiesa, Liscio, Canale Nord and Canale Sud shows a greater number of buildings with values between 20 and 30. While lower scores between 10 and 20 are present on the Contrada of Portella and Northern Pecorini. Lower scores from −10 to 10, are uniformly distributed on all the Contrada with a total of 23 buildings out of the 173 surveyed. In particular, 15 buildings have a score lower than 0; since 14 of these are in a state of ruin, which has been assigned a value of −30 by default, the building with a negative score is actually only one.
In the macro-area Structure (Figure 13
), the results show an average value slightly higher than 19. However, observing the distribution within the Contrada, it is noted that mostly of the buildings of Pecorini North and Canale Sud present values between 20 and 30. This result reflects the fact that Pecorini Nord is a Contrada with a high number of residents, thus, it has undergone substantial renovation of the buildings, including on structural aspects, preserving the characteristics of traditional architecture. On the other hand, in Valdichiesa and Portella the buildings gather on the side of a slope; thus, they add up to lower values. Finally, more than 50% of the buildings in Liscio have a value greater than 20.
The macro-area Energy has lower values than the other two (Figure 14
). No building can reach the maximum score of 30 and the best of cases reaches a value of 26. The average value is slightly lower than 11 and most of the buildings are in values between 10 and 20.
In this macro-area, the various Contrada have rather uniform scores; only Liscio one has a higher quality linked to restructuring interventions involving renewable energies.
The lower scores obtained in this category, compared to the others, depend substantially on two factors: the seasonal use of most of the houses and the sporadic appeal of RES (Renewable Energy Sources).
As regards the first aspect, it must be considered that Filicudi between summer and winter increases the number of inhabitants by about 10 times due to the arrival of tourists and the return of emigrants. Thus, the energy consumption of most buildings is in itself reduced, given the lack of use during the winter months. For this reason, the payback time on energy improvement measures would be fairly long. This makes this kind of refurbishment unattractive to the individual user.
For the second question, the use of RES is almost completely absent despite it playing a very important role in achieving a good score in the Energy category. The sporadic use of photovoltaic systems, solar thermal systems and the complete absence of micro-wind power is linked to the high cost of installation and maintenance, due to the difficulty of accessibility of the isle. This happens despite Filicudi having high annual global solar radiation values of 1622 kWh/m2
] and average annual wind speed of 11 km/h [62
Nevertheless, with a standard deviation less than 8, the score remains above 0.
In addition to the analysis for each of the individual categories, the tool allows for a complete analysis of the global data (Figure 15
and Figure 16
), and therefore of the overall quality of the building. The thematic on the global datum (total score) makes it possible to identify immediately the buildings that are in a critical situation (set for the two score ranges between −30 and 10) and buildings that have a high quality (established for score the two ranges between 50 and 90). Analyzing the data, it can be seen that more than half of the buildings surveyed reach scores above 50, with a maximum value of 76, not very far from the maximum score achievable by the evaluation system equal to 90. The district with better quality of buildings it is Canale Sud, consisting of buildings mainly owned by non-native people, today, however, residents on the island, and restructured in an exemplary way. On the other hand, the districts inhabited by the indigenous population of the island, such as Pecorini Nord, have a much lower level of general quality. This paradoxically shows a lower sensitivity of residents towards traditional architecture, often combined with a lower economic availability for recovery interventions.
The tool also allows the creation of specific queries, identifying the distribution of a specific data. For example, by analyzing two themes in the macro-area Energy, namely, rainwater collection and photovoltaic panel (Figure 17
), it can be seen that the first relates to almost all of the buildings, while the second is rare. This possibility of analysis makes this tool suitable to plan the refurbishment purpose. In fact, you can image different scenarios and compare the effect of them in the improvement of the building’s quality. The survey tool allows to direct interventions on the entire territory in order to raise the total score and hence the overall quality of the building. This is the main goal, more than the redevelopment at the level of the project of the single building, for which a detailed survey certainly provides a more specific tool. Thus, this tool can be particularly useful for directing the capitals that at the community or national level are often allocated for the revitalization of marginal areas.
During the study, the application of consolidated tools for reading and addressing strategies for the recovery of existing buildings, namely, the REM and the GIS, was tested. Their interrelation has allowed the creation of a flexible and innovative reading tool. The adoption of a REM methodology has made it possible to contain the execution times of the study, while maintaining a large amount of data collected.
Having implemented the analyses conducted with the REM tools on a GIS platform made it possible to systematize the results obtained. The GIS tool leads to a double level of reading. It is in fact a tool for those involved in safeguarding and enhancing (administrators, technicians, builders, etc.), and for those who do not have specific knowledge in the matter (property owners, local associations, etc.).
The first one constitutes a useful pool of knowledge to draw on when dealing with the project of recovery or re-functionalization of the architecture of the place, providing data on the state of the places with respect to their original configuration and conformation. The results of the final analysis provided a sufficient level of detail to identify the critical factors as well as the potential (e.g., too high energy consumption, low use of renewable sources, sufficient seismic safety conditions, loss of traditional characters and integration in the environmental context).
For those without specific knowledge, it is an index of the state of health of local real estate. The instrument is in fact able to provide an intuitive index of the quality level of the property, as well as a rough indication of what the priorities for intervention are to improve it. Compared to the current evaluation methods (energy certification, seismic classification, etc.) the method proposed has the advantage of being multidisciplinary and flexible. In fact, the subdivision of the data collected into separate categories facilitates reading and allows the identification of critical issues more easily.
The DOCET analysis served as validation tool. Figure 11
shows that the average low level of energy performance results both from REM and from DOCET. The specific energy consumptions range from a minimum of 56.0 kWh/m2
to a maximum of 127.0 kWh/m2
, while the energy classes are between the C and the D. While the score for the macro-area Energy goes from 13, which correspond the building with the worst energy class (i.e., D), to 22. Thus, the substantial correspondence between the energy score and the energy classification carried out by DOCET, as a draft, permitted to assert that the methodology adopted to provide more than acceptable results. With regards to the energy consumptions, it can be observed that the building selected for the Contrada Canale Nord is not very well representative of the Aeolian Architecture, as also shown by its very high S/V ratio (higher than 1.0). Thus, excluding this value, the average energy consumption is 67 kWh/m2
, which could be assumed as reference values for the buildings to achieve an energy score of about 20. Finally, considering that the highest achievable score is 30, it will be possible to foresee refurbishment work specifically designed for each building, since it is known which its specific points of weaknesses are.
The medium-high level of seismic safety condition that result from REM were validated by visual analysis of masonry cracks. Even if seismic events affect the Aeolian archipelago periodically, the crack of the Filicudi building walls is slight.