## 7 Conclusions and Future Directions  
The standardization work of the BIM2 IndiLight project resulted in the description and validation of around 400 parameters for daylight, artificial light, and facade systems. These standardized parameters form a solid foundation for defining exchange requirements and support consistent semantic communication between BIM and BEM. By integrating these parameters as a library into the BIM2 BEM-Flow, mapping for DALEC and PHPP was prepared. Key Findings and Recommendations:  
* Comprehensive Parameter Libraries: This research demonstrates that well-defined parameter libraries are essential. They not only provide consistency for early design simulations but also reduce manual rework. In our approach, these libraries are the backbone of the BIM2 BEM workflow, supporting both project-specific needs and standardized exchange requirements. * Flexible, Toolchain-Based Integration: While standardized parameters lay the groundwork, flexible mappings--including default value libraries and threshold libraries--are necessary to address rapidly evolving project demands and cross-border differences in standards. This flexible toolchain approach enhances the interoperability between BIM and BEM by automating data validation and ensuring the correct export of IFC files. * The Role of the YAPS (Parameter or Property) Manager: A newly established role is critical to the process. The YAPS Manager is responsible for creating, curating, and maintaining libraries. Public libraries maintained by reputable software companies or industry committees can not only reduce the workload for individual projects but also enhance data trust and consistency across the AECO sector. * Early Design Optimization: By integrating standardized parameters with default values into the BIM model early in the design process, architects and planners can conduct energy simulations and performance assessments sooner. This early design optimization enables rapid iteration and more informed decision making, which is crucial for improving overall building performance. Revisited Research Questions:  
1. How can project and tool-specific parameters make the integration of BIM and BEM more efficient? Our findings show that standardized parameters--when combined with flexible mapping and automated toolchains--establish a common data foundation. This approach streamlines data exchange, reduces errors, and supports early-stage energy simulations, thus promoting design optimization and better collaboration among AECO stakeholders. 2. To what extent can flexible, tool-chain-based approaches close the existing gaps? Standardization alone struggles to address the evolving requirements and complexity of modern projects. By incorporating toolchain-based solutions (like the BIM2 BEM-Flow system) with API-driven integrations, default value libraries, and role-based responsibilities, the approach not only automates property management but also adapts dynamically to project-specific needs. This method paves the way for broader interoperability, provided that BEM software vendors enhance IFC support for alphanumeric data. * Standardization vs. Flexibility: Creating a standard that is both flexible and scalable remains a challenge. Future work should focus on developing public libraries that can be updated quickly and adapted to both national and international requirements. * Interoperability in Practice: While our approach successfully integrates parameters into BIM workflows, many simulation tools (aside from DALEC and PHPP) still do not support the import of alphanumeric data via IFC. Collaboration with software vendors is needed to optimize this process. * Parameter Management and Redundancy: As property libraries grow, managing redundancies and conflicts becomes increasingly complex. Dividing libraries by simulation tool and establishing clear rules for managing overlaps are promising solutions. * Long-Term Dissemination and Industry Acceptance: The current work is experimental and has not yet been validated by independent companies.