Part 14: Lands Collide - External References


External references, or xrefs, links another drawing to the current drawing. The objects in the xref appear in the current drawing, but the objects themselves are not added to the drawing. When you attach an xref, any changes you made to the original are automatically reflected in the drawings that reference it.

External References

You can attach an entire drawing file to the current drawing as a referenced drawing (xref). With xrefs, changes made in the referenced drawing are reflected in the current drawing. Any changes to a referenced drawing are displayed in the current drawing when it is opened or reloaded.

When using referenced drawings, you can:

  • Coordinate your work with the work of others by referencing other drawings in your drawing to keep up with the changes being made by other designers. You can also assemble a master drawing from component drawings that may undergo changes as a project develops.

  • Ensure that the most recent version of the referenced drawing is displayed. When you open your drawing, each referenced drawing is automatically reloaded, so it reflects the latest state of the referenced drawing file.

  • Merge (bind) attached referenced drawings permanently with your current drawing when the project is complete and ready to be archived.

Complex Object as a Separate Drawing

There are commands within proprietary application programs that can turn an object(s) or portions of a drawing into a new file. One such program is AutoDesk AutoCAD 201x, where you use issue the “wblock” command to “write out” the  object/block into its own separate drawing.

External References aka “Overlay”

A drawing file can be attached or “overlayed” as an xref to multiple drawings at the same time. Conversely, multiple drawings can be attached as referenced drawings to a single drawing. You can keep the names of layers, dimensioning styles, text styles, and other named elements in your drawing separate from those in referenced drawings.


Similar to a block, an xref appears in the current drawing as a single object.

However, you cannot explode an xref without binding it first.

For more information, along with illustrations/animations/short quiz, please Click Here.

Part 14: Lands Collide - External References