For this example, I am using some drawings of a simple office plan, and these drawings are the work area, the washroom, the meeting room, and the lift area. You can use your own set of drawings for this section as well.

In the following example, we will learn how to add our to a drawing as an XRef:

1. Open a blank drawing, and then type UN and press Enter. Set the unit of this drawing to inches and the length type to decimal in the Drawing Units window.
2. Click the Attach button in the Reference panel of the Insert tab, as shown in Figure 9.1:

3. The Select Reference File window will open. Change the file type to DWG in this window, as shown in Figure 9.2, then locate the drawing you want to insert and click Open. In this case, I am inserting the Work area drawing:

4. Now, the Attach External References window will open, with lots of options. We will explore all the options in this panel in a moment, but for now, select Relative path as the Path Type and Attachment in the Reference Type panel. Leave the other options at their defaults.
5. Click OK, and then click on any point in the drawing area. We now have our Work area drawing added to the current drawing as an XRef.
6. If you don’t see the drawing, or if it's too large or small, double-click your middle mouse wheel to fit the XRef in the drawing area.
7. The XRef added to the current drawing will appear with 50% transparency, as shown in Figure 9.3. This is one of the characteristics that will help you identify it in a drawing:

The Work area XRef added here is like a link with a preview. The Work area drawing looks like it's added to the current drawing, but it's not entirely like that. The drawing is added here only as a linked object. To understand this properly, we will modify the original Work area drawing and see its effects on the current drawing:

1. Save the drawing in which the Work area XRef has been added and give it a name. I will name it main XRef for this example.
2. Open the Work area drawing, delete the pillar next to the plants, and then save your drawing. If you are using your own drawing, then make any change in it and save it. After saving, close the drawing.

3. Now, go the main XRef drawing, and you will notice an exclamation mark right next to the manage XRef icon of the status bar, as shown in Figure 9.4:

4. Right-click on the icon and select Reload DWG XRefs from the context menu, and you will notice that the attached XRef will update in the current drawing as well, and we will no longer have a pillar in our attached XRef.

So, this is how XRefs work. Once attached, they become part of the drawing, but they can still be modified from the original drawings and the changes will appear in the drawing where they are attached. Before we learn more about XRefs, let's talk about the Attach External References window and its options in the next section.