5.0 Graphical/Geometric Object Modelling

This section of the standard defines the generic modelling requirements for the graphical element of the BIM object.

5.3 What to model

  5.3 What to model
This sub-section of the standard defines what should and shouldn’t be included in the geometric model of the object, such as maintenance zones, hidden content and other spatial requirements.
 5.3.1 Pre-planning
  The geometric modelling of the object shall be planned, including any parametric relationships, so as to consider what graphical detail is required/necessary and what information will be visible in different views.
Note: Small elements or non-critical elements of the object may not require modelling as these may impact model performance.
 5.3.2 Detail
  The object shall represent the form of the physical element’s external boundary without providing excessive or unnecessary detail.
Detail that would not be visible (or hidden), should not be modelled, unless required for the intended BIM use.
For example, the face of a chest of drawers only need show the face of each drawer, the drawer itself shall not be modelled.
 5.3.3 Connection points
  Objects that are required to connect to other objects, such as a fan unit to a duct, shall have the relative position of their connection points accurately modelled.
 5.3.4 Spatial requirements
  Objects representing physical elements that have spatial requirements, such as clearance zones, operation zones or maintenance zones, shall also have such spatial requirements modelled.
The modelled spatial requirements shall have their visibility controlled, with the default being that the spatial zones are not visible.