Together with the regulations for building models, the FDK defines the cross-project data requirements of the BIM method at SBB. It ensures that the structure and semantics of the models are standardised across all projects and that the models contain all the information required by SBB.

The FDK defines all object types (elements, installations, etc.) and their properties (characteristics, attributes) that SBB can require in the various discipline-specific models as part of a project. The FDK also contains further information on how the property sets are defined or how the mapping to the IFC schema, the discipline-specific models, and the element-based construction cost plan (eBKP) should be carried out.

To create models for SBB, suppliers should adhere to the specialised data catalogue. This describes which object types should be modelled, how they should be structured and named, and which properties the objects have.

SBB updates the specialised data catalogue in regular releases and publishes it online as a website and as an Excel file. From spring 2025, SBB will also use the FDK as a basis for defining project-specific data requirements. These are presented in the openBIM format IDS and are part of the tender documents for planner submissions for BIM projects.