1. Part 14: Lands Collides
- External References

2. Objective Of This Lesson
Identify what external references are and how they are used.

3. Overview
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.

4. 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.

5. External References (cont.)
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.

6. External References (cont.)
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.

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

8. Drawings as reference files (cont.)
We will discuss and illustrate how drawings are used as reference files within one another.
The pictorial drawing to the right was constructed using several separate drawings.
Each separate drawing was designed individually.
When worked upon each was used as a reference file, or background to one another.!

9. Drawings as reference files (cont.)
Doors
Drawings as reference files (cont.)
Windows
Xref-Architectural geometry
Walls,
interior
Shows:
Walls (Ext. & Int.)
Doors
Windows
Room opening
Stairs
Walls, exterior
Room
openings
Stairs
Doors

10. Drawings as reference files (cont.)
Restroom
Xref-Furniture Layout
Kitchen
Shows:
Kitchen
Restroom
Lounge
Conference room
other furnishings . . .
Lounge
Conference

11. Drawings as reference files (cont.)
Restroom
Xref-Utilities Layout
Enlarged Detail
Kitchen
Shows the location of the room electrical outlets recessed in the wall.
Lounge
Conference

12. Drawings as reference files - Additional example
Xref-Roadway
Xref-Parking
The roadway drawing to the right was constructed using several referenced drawings.
Xref- Utilities
Xref- Recreation
Xref- Vegetation

13. Drawings as reference files - Additional example (cont.)
Let’s say we rotate the pool 90 degrees on the Xref-Recreation file.
We would then have to make the necessary changes to the
Xref-Vegetation file.

14. Part 15: Sharing Our Discovery - Setting Up and Plotting a Drawing
The preceding was just a general overview to make one familiar with what's involved in understanding and using CAD
Up Next:
Part 15: Sharing Our Discovery
- Setting Up and Plotting a Drawing