## 3 Results
### Thematic Analysis of Selected Articles
#### 3.2.4 Building Data Management  
The last topic of investigation concerns data and related management, which includes availability, collection, and organization. One of the primary benefits of the digital building logbook is enhanced data accessibility for stakeholders, including building owners, managers, and regulatory authorities. Effective data management in the digital building logbook allows for the seamless sharing of information among stakeholders. This is essential for collaboration and ensures that all parties have access to the most current and relevant data, which enhances decision-making processes throughout the building lifecycle. By categorizing stakeholders as data providers, data users, or both, the digital building logbook can streamline the flow of information and clarify responsibilities, which is crucial for effective data exchange [25].  
As stated in the previous sections, there is no uniform model for the digital building logbook, and hence, the data required differ among countries. Regarding data availability, in a country like Italy that has regional construction legislation, there are a lot of data available at the national level but sometimes some geographic data are available only at the regional level. According to [PERSON] et al., municipalities of federalized countries should focus on centralizing data so that they can be supplied through regional digital building logbooks, and then countries can provide a link to national digital building logbooks. Following the examined study, the available data do not completely correspond with the relevant indicators outlined in the existing proposals for a European digital building logbook framework. Additionally, only a limited number of data sources are currently compatible with the digital building logbook, as the majority are not interoperable [36]. Recognizing that data sources for the digital building logbook can be both open and proprietary, [PERSON] et al. highlight the role of ontologies in extracting, representing, storing, retrieving, and analyzing machine-readable information. They can facilitate data integration and exchange by providing a structured framework and specific vocabulary to describe buildings from various contexts [29].  
Concerning the information currently available about buildings, there is a need for additional data collection. To fully leverage the digital building logbook's ability to promote renovations and enhance energy efficiency, it is essential to gather information on actual building performance (including needs and consumption), interior conditions, and user behavior. The rapid growth of networking capabilities has led to challenges in managing the vast amounts of energy consumption data generated by buildings. Most of the data that have been collected are either not publicly accessible or are not stored in databases at all. This situation limits the potential usefulness of the data. Renovation efforts can be hindered by the inefficient querying of these data, which are often stored in data lakes and warehouses. To address this issue, promoting open data is essential, while always ensuring compliance with the General Data Protection Regulation (GDPR) [33; 36]. The ALDREN initiative aligns with broader EU strategies aimed at enhancing building data management and improving resource efficiency across the construction sector. It seeks to overcome barriers like data fragmentation and privacy concerns that have hindered the implementation of such systems in various EU member states [40].  
Finally, some papers discuss how blockchain technology can enhance the reliability and trustworthiness of construction logbooks. By utilizing blockchain, the information recorded in logbooks can be securely logged and timestamped, ensuring data security while maintaining public access to non-sensitive information. This addresses issues of data tampering and provides a clear audit trail for all activities on construction sites [27; 30; 39].