AutoCAD 12 and higher versions

Today, I will start my series of articles, to explain what XREF objects are and how to use them in your drawings. Let’s quickly start with an example.

Fig. 1

In the example, you can see a single room. Let’s see what are the furnishings in this room (Fig. 2).

Fig. 2

In this figure, there are two separate drawings. What we are going to do is, to make these two separate drawings meet in the same drawing. Most of the project draftsman handles this drawing in one drawing only. Thus, they prepare furnishing and architecture in the same drawing. Although there are some certain advantages of working in one drawing, there are many disadvantages also. However, it is very useful to make drawings separately in different disciplines and then combining them in the same drawing by using XREF. Let me explain these advantages:

• First of all, floor plans are not made up of one single room as shown in this example; most of the time, we deal with floors that are made up of 20-100 different rooms.
• In such comprehensive projects; furnishing, electrical, mechanical and structural drawings are prepared by different companies, and each company prepares their own drawings.
• In traditional approach, revisions that is made over the architectural drawings are informed to these companies and send to them as one drawing and the companies revise their own drawings accordingly. However, in XREF solution, the others can directly see any revision.
• Works that are made in different disciplines directly reflect to the main drawing.
• As all the drawings that are inserted into the main drawing as XREF are counted as one single drawing element, they can be very easily controlled.
• Revision controls are very easily done.

Now, let’s take a look at how the XREF principle works: We have a project named as OP-ROOM and it represents an operation room. Let our architectural plan be OP-ROOM-ARCH.dwg, and the furnishing plan be OP-ROOM-EQUIP.dwg . I would like you to pay attention to the names of drawings (Fig. 3).

Fig. 3

After naming is finished, let’s execute XREF command. You can enter this by using XR abbreviation or from ‘Insert/External References…’ menu. When you enter command, XREF palette will open up (Fig. 4).

Fig. 4

On the top of palette, there is a button menu. The button on the left is a pull-down button and it is used for attaching a drawing, picture of DWF file. As we are dealing with drawings at this point, let’s select OP-ROOM-ARCH.dwg by using ‘ATTACH DWG…’ option. After selecting the drawing, a new window, which is similar to INSERT command, will open up. Note that, XREF is actually an advanced block and acts as a block inside the drawing, only difference is that it has some additional properties (Fig. 5).

Fig. 5

At the upper section of the window, there is file path, reference type and type of storing the external reference. It is same as the INSERT window. At this stage, reference type will be ‘Attachment’. ‘Overlay’ is used for drawings that you want to use as template and its behavior is totally different. ‘Path type’ defines how the path information of the other drawings will be stored. If ‘Full path’ is selected, then the file name is stored by using the complete file path. In this case, if you send your drawing to another place, then the same file directories must be present in the new computer also. If we select ‘Relative path’, then this means that the sub-drawings are present in the same directory. Thus, this is the best choice. After adjusting the properties, insert your XREF block at 0,0 point. Note that, insertion point and the origin points of other discipline drawings must be exactly same. Let’s do the same for OP-ROOM-EQUIP.dwg drawing also. Your drawing will look like as shown in Fig. 6.

Fig. 6

The real magic starts here. Now, let’s open OP-ROOM-EQUIP.dwg drawing and change the location of one of the drawings and then save (Fig. 7).

Fig. 7

Now, let’s close this drawing and return back to the main drawing. Through the XREF window, let’s enter OP-ROOM-EQUIP.dwg drawing to the concept menu ( by clicking on it with right mouse button ) and select ‘Reload’ option from the menu (Fig. 8).

Fig. 8

You will see that the furnishing revisions are immediately updated in the main drawing ( Fig. 9 ).

Fig. 9

In my next article, I will explain about the other properties of XREFs inside the drawings.

Have a nice day.

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