When elements intersect, a typical example is where masonry walls are constructed around structural columns, modelling results in walls continuing through the columns.
While this may not be visually apparent in some contexts it obviously affects both drawing production and scheduling of volumes. The wall must be modified to accurately represent the construction.
This can be done using the Subtract Solid tool. When the elements involved are columns and walls created with OpenBuildings tools it is important to use the Subtract Solid tool from the Building Design ribbon:
This video demonstrates the technique. When using new or unfamiliar tools always take note of the Status Bar prompts: