## 4 Methodology  
To address the challenges of interoperability between BIM and BEM, this research draws on two interlinked projects: BIM2 IndiLight and BIM2 BEM-Flow. These projects span the period from 2017 to 2025 and represent a phased approach to address the issues of parameter standardization and workflow optimization. The first project, BIM2 IndiLight, focused on researching and validating exchange parameters for daylighting, artificial lighting, and facade control systems. Through extensive data collection and analysis, over 400 parameters were identified, validated, and documented to establish a foundation for standardized information exchange. Building on these results, the second project, BIM2 BEM-Flow, aimed to translate the theoretical findings into practical tools. In this phase, the focus was on developing a toolchain consisting of two web-based applications and a Revit plugin. The objective was to enable efficient management, assignment, and coordination of project- and  
Figure 5: Conceptual relationships between International Norms (ISO 19650-1 [16], ISO 17412-1 [28], and ISO 29481-1 [29]) (slightly changed by adding categories (gray boxes)). company-specific parameters and to simplify their integration into BIM applications for energy simulations. This section describes the methods used in these projects, including data collection, development processes, collaboration with stakeholders, and the integration of tools and technologies such as Revit. Together, these efforts constitute a holistic strategy to improve interoperability between BIM and BEM. BIM2 IndiLight (2018-2022): Research and Validation of Exchange Parameters for Daylight, Artificial Light, and Facade Control  
The motivation behind the project was to expand the ASI property server with selected and validated properties from the areas of daylighting and artificial lighting, shading systems, and their control in order to advance their standardization. The properties from the DALEC calculation tool were also compared with these standardized properties and, if not already mapped, incorporated. In addition, the validated parameters were compared with IFC2x3 and the new IFC 4.3 standard (ISO standard 16739 [12]) to identify overlaps. Although the resulting standardized parameters were originally published on the ASI Property Server, a change in the ASI's structure and strategy has since rendered these results unavailable. By offering predefined, standardized properties, detailed information (such as phase and exchange scenarios) can be accessed and implemented directly, bypassing the lengthy, complex, and error-prone process of manually defining these properties. As a result, using standardized properties can streamline tasks like those illustrated in Figure 6.  
To facilitate the standardization of properties during the BIM2 IndiLight research project, four task groups were established, involving representatives from the University of Innsbruck, HELLA Sonnen- und Wetterschutztechnik GmbH (Abfaltersbach, Austria), and Bartenbach GmbH (Wattens, Austria) (see Figure 7). These groups identified the properties necessary for information exchange with the DALEC simulation tool and for describing components related to daylight and artificial lighting, such as shading devices, lamps, and luminaires. Additionally, properties related to sensors and controls were defined to support personalized daylight and artificial lighting control [33]. This process followed a methodology previously used successfully in the standardization of component descriptions for the ASI Property Server, resulting in the creation of a dedicated BIM2 IndiLight library [34]. Figure 6: Simplifying and standardization the process of defining the Asset Information Model. Relevant standards and guidelines were first reviewed to identify and document the most important properties (see Figure 7).