SIMULTAN ComponentBuilder plugins enable individualized development of connections to simulation tools, easing data management of the simulation-driven interdisciplinary planning processes in civil engineering. The Software Development Kit (SDK) is an integral part of ongoing research projects, which aim to exhibit and expand the capability of the SIMULTAN Meta Data Model. The goal is to store digital information necessary for the planning processes in civil engineering and operation and operational performance analysis of buildings via digital twins. A theoretical outline of the plugin structure is given, and the usability of the SDK is shown by presenting two example plugins. Two plugins were developed to enable seamless integration with the proprietary simulation software IDA ICE and RFEM 6 within the same data model. Furthermore, it is shown that the existing data in the SIMULTAN Data Model can be reused by utilizing already existing information and avoiding duplication. Limitations of the SDK will be explained, and concepts for future data model extensions will be discussed. The development and deployment of the two plugins show the benefits of using a Big-open-real-BIM Data Model for civil engineering planning processes, enabling individualization and workflow-enhancing expansion.