Direct Answer
A reference model is an external model (IFC, DWG, DGN, or other format) imported into Tekla as a non-editable visual reference. Structural detailers use reference models to see the architectural, MEP, or civil context around the steel — detecting clashes, verifying clearances, and coordinating penetrations — without needing to model those elements in Tekla.
Full Explanation
Reference models are loaded into Tekla via the Reference Models tool and display alongside the native steel model. They are view-only — you cannot select or modify reference model elements, but you can measure to them and use them for visual clash detection. Common reference model sources: Revit architecture exported as IFC, MEP models exported as IFC or DWG, civil site models in DWG. The reference model updates when you reload a new export from the source — which is essential for keeping coordination current as the project evolves.
What This Means for Your Shop
Insisting that your detailer loads and reviews the architectural IFC as a reference model before issuing shop drawings can catch dozens of coordination issues — particularly at slab edges, exterior wall interfaces, and mechanical room framing — before they become field RFIs.
Common Mistakes
Loading a reference model at project start and never updating it. If the architect revises the building envelope or the MEP contractor reroutes ductwork, an outdated reference model in Tekla won't show the conflicts.
Recommended Process
Establish a reference model update schedule (aligned with the project's BIM coordination rounds). When the GC or BIM manager issues updated trade IFCs, load them into Tekla and run a visual clash review before the next shop drawing issue.