5. Conclusions
This paper has illustrated the growing body of the research, with a focus on existing methods, used to select and assess appropriate retrofit operations, explaining their gaps and challenges; then, an explanation of the first findings of this study have been conducted, with a first draft of the methodology - final product of this study - and a case studies selection.
As shown by the analysis of the Guidelines, the existing procedures do not allow to have a global view on the choices effect; consequently, it leaves the assessment of measures as a simple comparison and risk evaluation, without however balancing the whole. On the contrary, interventions should improve the performance on the entire building (whole building approach), taking into account heritage and users needs, according to the use of the building and its constructive and material characteristics. Ancient buildings have a different behaviour compared to those of new dwellings, as their thermal properties guarantee fair performance, especially in hot climates. It could be counter-productive to "seal" these buildings because of their need to “breathe”[36]. Measures have to be defined as long-term strategies and optimize the existing resources, aiming to comply with the compatibility and minimum intervention criteria.
The exposed considerations have demonstrated the need for a new methodology for the evaluation of retrofit measures, that could be integrated in the existing Guidelines. The aim of this research is, therefore, to define an holistic and multi-criteria procedure, to help professionals and public administration in the elaboration and evaluation of retrofit actions.
The final product of this research would to be a guidance tool, able to direct the planning and assessment phases case-by-case, according to the common criteria and single objectives established before. Hence, the first draft of the procedure has been explained, showing the different structure of the planning process – bottom up approach – and the assessment process – top down approach. This procedure aims to be a implementable and interactive open tool, useful for end-users, to save energy, money and guarantee the building preservation and thermal comfort; for consultants and contractors like Public Administrations to monitor retrofit interventions and achieve environmental goals; for professionals to select the better choice in terms of conservation of the heritage asset, operational cost saving on the long-term, energy consumptions reduction.
Case studies are useful to validate the proposed procedure: the selection of case studies was organized into a process. It has been developed into three phases: inventory of buildings, classification and selection of representative buildings. The first phase of the process consists in identifying and collecting the data available on the considered buildings. Information on buildings has been derived from what is extrapolated from the data available and provided.
For their classification and selection, the following parameters were chosen: building identification, building typology, building use category, climate zone, construction period, protection constraints, energy consumptions (if available - in some cases there are no plants, as common in many historic buildings). Finally, 15 buildings have been selected, including also few examples out of the classification for their particular characteristics (e.g. no plants; degradation problems; multiple function; building with modern additions; etc), to extend the analysis perspective.
In the next steps will be defined more in details objectives and targets for building categories. After that, single steps of the procedure will be established and for each case, both with a desk and a field methodology, pros and cons of possible measures and interrelated alternatives would be expressed, giving life to a complete overview of the building system.
The proposed approach aims to be different from the traditional design/assess process, as it allows the stakeholders to explore the integration of all improvement scenarios, including non traditional solutions, to save energy, reduce environmental impact and preserve the building heritage.
6. Workplan and Next Steps
The workplan consists of 5 work packages. During this first year and a half of work, the first WP was completed while the second one is nearing completion, namely:
- WP1 – Knowledge Phase: literature on retrofit of cultural heritage (especially in
Mediterranean climate) and on assessment criteria for historical building is collected. The first phase is fundamental to build the useful knowledge base, in order to face the future steps of the research. The main outputs are: state-of-art elaboration (that it continuously uploaded); review of existing instruments and tools for survey procedure; exploitation of the most common retrofit measures from literature; overview of legislative scene and official guidelines. Case studies analysis and categorisation: case studies have been collected and dataset analysed and integrated with needed informations. It is useful to go in depth in the research procedure. Final output produced is an abacus of case studies.
- WP2 – Definition of gaps and challenges of existing Guidelines: Mibact and European Guidelines’ procedures have been applied on case studies, comparing results and highlighting problems in their application. This is fundamental to built a new procedure to be implemented in these documents.
Definition of Targets of Case studies (on-going): this phase serves for the recognition of the targets used in the literature to evaluate the optimal state of the building, in relation to its use (museum, library, office, etc.). The final product will be the recognition of minimum indicators required for each building category, with relevant measurement intervals considered to be acceptable.
In the next steps will be defined more in details single steps of the procedure, as explained in the WP3:
- WP3 - Multicriteria Decision Tool Definition and Validation: the goal is to define an holistic multicriteria tool, useful to help during the planning process (Bottom-up) or during the assessment phase (Top-down), validated through case studies.
- Definition of the procedure structure (steps of the guidance tool);
- Definition of guiding criteria of general validity for all cases;
- Definition of general objectives for each building categories (museum, library, office, church, multiple use) with relative targets;
- For each target, benchmarks will be identified.
- Measurements and diagnosis will be suggested to fulfill objectives and targets (e.g. if the objectives is hygrothermal behaviour and the target is degradation removal, water content measurement can be suggested, etc) and references;
- Case studies application: evaluation of needs and problems of the places and their needs with an on-field methodology; then, a desk-methodology will be adopted to verify a list of measures with a simulation phase able to assess pros and cons of each strategy and possible interrelation of actions.
Final outputs will be the procedure development ; this last part would also increase the technical culture of the sector, improving knowledge on Mediterranean area.
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WP4- Best practices exploitation: this a workpackage that could be added at the last part of the project where non-standards solutions will be explored, also, if possible, with experimental test on case studies.
- WP 5 - Dissemination: this phase accompanies the research path.