# Hydrothermal Behavior of Cultural Heritage Buildings and Climate Change: Status and Main Challenges
## 5 Knowledge Gaps and Future Research  
Reviewing the papers related to the combined topic--Hygrothermal Conditions--Cultural Heritage--Climate change, published until 2022, allowed to run a global debate on the trends and limitations of this triangle, aiming at pointing out future research directions. The answers to the initial research questions are listed as follows:  
1. the state of development of this research field is in its infancy. Examining the articles resulting from the literature review, it can unquestionably be stated that this combined topic is practically unexplored. Not only does the first publication on the matter dates from 2003, as the average number of publications per year is still very small;
2. the analysis and discussion on this matter suggest that until recently, greater research emphasis has been related to the traditional view of cultural heritage protection from a preventive conservation perspective and that only the papers published in more recent years openly address CC--and still without considering the refurbishment and/or (re)adaptation of CH buildings for climate changes;
3. the main research gap is definitely the lack of in-depth studies on climate scenarios. \"Climate change\" is used many times as a motivational buzzword but without direct applicability, e.g., evidence of its real impact is lacking. Following this purpose, the authors recall [PERSON] question [PERSON] (1994), on the thermal performance of the traditional building envelope in Scotland, still unanswered:  
1. how it can be improved without compromising the essential vapor dynamic that characterizes traditional construction?
2. how to address embodied energy issues?  
The risk to CH buildings from CC is expected to increase in the future, and so, the inclusion of the following aspects should be considered in future analytical and/or numerical models, as well as in the laboratory or in-situ experimental campaigns, namely:  
* the impacts of the variations of temperature and precipitation profiles;
* the variation in the air pollution level;
* the forecast of extreme climatic events (e.g., heatwaves, droughts, storms, floods, seasonal shifts in climate, etc.);
* the variation in sea levels;
* the modification of soil conditions and groundwater, etc. In summary, this combined topic is very new and quite unexplored, and further research is required to assess how future CC scenarios will affect the hygrothermal behavior of CH buildings, in order to enable the scientific community to gain improvement in the investigation for diagnostics, namely through:  
* analysis and assessment of CH materials;
* identification of artistic techniques;
* identification of the reasons and effects of deterioration processes regarding the indoor environment;
* adaptation of preventive conservation standards/guidelines to future climate scenarios.
* in-situ monitoring before, during, and after intervention in CH buildings.  
These new understandings are also fundamental for all stakeholders and practitioners involved in topics related to heritage conservation/rehabilitation and assessment of the hygrothermal behavior of historic buildings, as they will allow to better predict the delay, acceleration, or worsening of CH buildings' decay.