4 Steps to Reduce your Civil 3D DWG File Size

Have you ever seen a drawing file you created with Civil 3D balloon in file size? Has this caused performance to take a nose dive?

The following steps should help you get some improvement on getting smaller file size, and hopefully better performance:

  1. Run an audit. An audit will detect errors and allow you to fix those errors. Sometimes files can become corrupted and contain things that will cause issues. Running an audit will help with this.
  2. Run a “-PURGE”. A what, you ask? I know what a purge is, but what is a “-PURGE”? -PURGE gives you a few options that the purge dialog box does not; namely, the REGAPPS option. REGAPPS are registered applications that essentially bloat a drawing and cause performance issues. While even Civil 3D creates regaaps, having a large number of them (more than 30 or so) can start to cause issues. I was in a DWG file the other day and when I ran this it came up with over 100,000 REGAPPS in the file! Check out the figure below to see just how many!
  3. If you are running Civil 3D 2014 and older, you need to go to the following link and download the DGN hotfix:
    What is this and why do you need it? This routine purges out un-referenced DGN linetypes. Running this routine, I have seen file sizes drop dramatically. “But I don’t work with DGN files and never have”, you say? It doesn’t seem to matter. Somehow, this routine can find stuff and clean up your drawing. Anyways, the previous link not only contains the files to download, but it also has instructions on where to put the files and how to load and run the commands. If you are running 2015 or 2016, you don’t need to download anything. Why? This is because the purge command in both 2015 and 2016 have a new check box option “Automatically purge orphaned data”. With this checked on, all orphaned DGN linetype data will be purged out. It will not removed all unused DGN linetypes however which actually gives the user the choice of keeping unused DGN linetypes or getting rid of them.
  4. 4. Finally, run a regular purge to see if anything else can be purged out. If the option to “purge out zero length objects and empty text objects” is not grayed out, check it on. This is another thing that even though you may not be able to see them, they can exist and cause issues. Check out the figure below that shows this option grayed out as well as the new purge orphaned data option.

Try these steps out and see if it at least helps out a bit. I have seen file sizes reduced by as much as 75% by following these steps.
By Ron Couillard, CADSoft Consulting
About Ron Couillard
Ron_CouillardCivil Infrastructure software is my main interest. I have been with CADsoft Consulting for over 9 years. I got my start using Softdesk and AutoCAD R12 in DOS.

This article was originally posted on the CADSoft Consulting Civil 3D Blog and is reprinted here with kind permission.