## 3 Results
### Thematic Analysis of Selected Articles
#### 3.2.1 Digital Building Logbook Structure and Data Categories  
The first analysis carried out focused on the description of the digital building logbook initiative. Only some of the reviewed articles include the presentation of a digital building logbook initiative. Despite numerous national initiatives focused on defining the concept and features of the digital building logbook, it is inferred that the so-called logbook still misses a uniform and standardized framework [2; 46]. A common set of indicators is absent and those vary greatly depending on the country and the category of building. However, since the implementation of the digital building logbook is a priority for Europe in order to boost renovation, efforts to create a common digital building logbook come mainly from H2020 projects such as iBroad, ALDREN, and X-tendo. Moreover, among the analyzed papers, there is a reference to national initiatives such as the German logbook Bauwerksbuch and the Spanish logbook Libro de Edificio [27; 39]. Figure 4: Research methodology adopted in selected records. A list of digital building logbook initiatives as represented in the analyzed papers is represented in Table 3.  
ALDREN (A Long-term Renovation and Energy efficiency Network) is a Horizon2020 project which has developed a digital building logbook known as the ALDREN BuildLog [48]. This tool serves as a comprehensive digital repository for crucial building data, including ownership details, design specifications, materials used, operational costs, and energy performance indicators [36]. The goal is to create a structured and easily accessible overview of a building throughout its life cycle, facilitating better decision making for renovations and energy efficiency improvements. It is designed to complement existing energy performance certificates and provides a clear picture of a building's current condition and its renovation potential [46]. The ALDREN BuildLog is modular and consists of six distinct modules that allow for tailored data collection according to the specific needs of building owners and managers. This flexibility is essential for creating a long-term renovation roadmap (referred to as the RenoMap), which outlines strategies for achieving energy efficiency targets [40]. The iBRoad project (Individual Building Renovation Roadmaps) developed the Individual Building Renovation Roadmap. It was a customized and long-term (5-30 years) step-by-step plan for building renovation [49]. A key feature of the iBRoad initiative is its digital building logbook, which serves as a centralized repository for all relevant information about a building [37]. Supported by a logbook with building-related information after an on-site building assessment and an interview with the homeowner, a trained energy auditor implements the roadmap [36; 46]. The auditor uses the iBRoad software (iBRoad-Plan) to present a step-by-step improvement plan, taking into account the homeowner's needs and preferences. Another Horizon2020 project that developed a logbook is X-tendo [50]. It aims to enhance building energy performance and improve Energy Performance Certificate (EPC) schemes using innovative tools. X-tendo developed a toolbox to help public authorities or implementing agencies strengthen existing EPC frameworks. This toolbox includes innovative EPC indicators, such as smart readiness and comfort, and innovative data handling, such as EPC databases, enhanced recommendations, financing options, one-stop shops, and building logbooks [36]. A logbook serves as a centralized repository for building data, aiding energy efficiency efforts and renovations. The BIM4 EEB Horizon2020 project developed a building logbook containing information related to the building as well, and it focuses mainly on the renovation the building is undergoing [51]. The tool is available on the digital platform BIM Management System (BIMMS) developed within the project, in which a specific section is reserved.