Revit to DWG Export – Some Layers Missing Custom Prefix

[pawel_kinczyk]

Hi everyone,

I’m facing an issue with DWG export from Revit and I’m trying to understand what might be causing it.

I have configured a custom layer naming setup where a prefix “ARC_RVT_” is applied to all exported CAD layers. In most cases (around 80%), this works correctly — the layers are exported with the expected prefix.

However, there are several layers that do not include the prefix at all, even though they appear in the same exported file. You can see this behavior in the attached screenshot — most layers follow the naming convention, but a few (e.g., A-FLOR, A-GENM, etc.) do not.

What I’ve already checked/tested:

• Prefix is correctly defined in Export Settings (both for Projection and Cut)

• Export performed with:

  • All Revit links unloaded

  • All imported CAD files removed/disabled

• In AutoCAD:

  • Tried Quick Select on elements from incorrectly named layers → no elements found on those layers

This makes it even more confusing, because those layers exist in the DWG, but don’t seem to contain selectable geometry.

Questions:

• Has anyone experienced a similar issue?

• What could cause certain layers to bypass the defined prefix?

• Could these layers be generated internally by Revit (e.g., system layers, empty layers, or export artifacts)?

• Is there a reliable way to prevent or clean this behavior?

Any insights or workarounds would be greatly appreciated.

Thanks in advance.

[lauri_barnhart]

Hi @pawel_kinczyk,

I wanted to check in and see if you still needed assistance, or if you found a solution to your question already? Let us know if you need further assistance by providing an update or if you have found a solution, please share it with the community so other members who may have the same question could learn from your experience.

All the best,

Lauri | Community Manager

[RLY_15]

Each of your errant layers in the screenshot has a corresponding layer with the correct prefix. If the no-prefix layers have no content on them, I wonder if Revit's export simply begins with these layers as default and then pulls in your naming setup afterwards.

If the layers are truly empty, you can probably run a script on the autocad side of things to just purge out the unused layers for a batch list of files.

[pawel_kinczyk]

Yeah, this is the way but I don't want to do this addition work... In that case, I could just add the prefix after exporting

[RLY_15]

You could. Either option is a lisp routine to make the process one-click instead of fiddling with the layer manager.

[lauri_barnhart]

Hi @pawel_kinczyk,

Did the info from @RLY_15 help answer your question?

If it did, it’d be great if you could click the "Accept Solution" button so others can easily find it too.

If you’re still needing more help, feel free to share an update here. The community will be happy to jump in with any next steps to help you get where you need to be.

Best, 

Lauri | Community Manager

[Nick.sipes]

@pawel_kinczyk can you post a screen shot from the Layers tab of the DWG Export Settings dialog? It's hard to determine why Revit is not exporting the layers correctly without understanding how the settings are configured. 

[pawel_kinczyk]

@lauri_barnhart unfortunately no. @Nick.sipes here are my export settings:

[Nick.sipes · Accepted solution]

@pawel_kinczyk,

I spent awhile today exploring this, as this is beyond what I normally do with DWG exports. Here’s the important part, when Revit exports to DWG it creates blocks for some of the families and types in the model. The linework in those blocks are assigned to the layers specified without any modifiers. The block instance is then assigned to the layer with the modifier name. This is how the layers A-FLOR, A-DETL-GENF, G-ANNO-DIMS, etc. are being generated. You can see this by running purge, switching to “Find Non-Purgeable Items” and selecting a layer as shown in the image below.

The previously mentioned LISP routine may be the most efficient solution. However, you asked for a Revit native solution, so below is a solution.

Copy the exportlayers-dwg-AIA.txt file from C:\ProgramData\Autodesk\RVT YYYY, where YYYY is the product year. Then edit the text file layer names, I used find/replace to test this, but you could also use a spreadsheet application. Once modified, follow the directions of Load Layers from Standard on this help page, https://help.autodesk.com/view/RVT/2025/ENU/?guid=GUID-3541F82B-9E25-47C5-BE52-3F6C6F40DA02. Revit will then export the way you are requesting. If the ARC is a project or building abbreviation, you can set up the base text file with a keyword like “[ProjectName]”, which will allow the use of Find/Replace per project.

[pawel_kinczyk]

Thank you very much! I tried to find this file for "export-setting" but i couldn't...