Each discipline is responsible for its own work. For example, the structural engineer is responsible for the load-bearing parts of the building which she/he calculates according to local design standards. This consideration requires that each discipline be able to edit and modify its own model, while using the others’ models only as a protected reference alongside their own. The models coming from the various disciplines, even if they may seem similar at first glance, are in fact quite distinct in their details. For example: the architects define the contour of a slab, using a slab element, while the structural engineer, doing design calculations with hollow core concrete slab panels, defines the final load-bearing structure. But the models of the two disciplines differ in several ways: in the element type used, size, number of elements used, level of detail in the intersections, and the relative positions of the elements.
A basic tenet of model referencing is that data loss, whether geometrical or other data, is not permissible.
The “geometry” part means that a referenced model element must be shown in our own project with its original geometry and position. The “data” part means that the reference model has to contain all data relevant to collaboration with the other discipline. For example, relevant data for an architect include the exact material and profile data defined by the structural engineer in the structural model.