ArchiCAD Modeling Using CAD plans - Importing DWG files

Modeling using CAD plans is a frequent situation, whether making as-built models or modeling on the basis of the team's CAD plans in a project.

The first thing to do is to import the CAD aplans into the project, it’s a simple task but as ArchiCAD is giving us some options of how to do that, there’s a few things to say.

There’s three option of how to import a CAD drawing into the current project:

• Merge a DWG file
• Attach an Xref (External Reference)
• Place an external drawing.

To choose from these options, it’s important to know how each one works.

Merge a DWG file (or DXF):

To merge DXF or DWG format files into the current ARCHICAD Project, use:

File > Interoperability > Merge form file (or form BIMcloud).

After choosing the file, in the Merge DXF-DWG dialog box, you have the option of merging the content of Model Space (in AutoCAD) into the current View, or to Merge (Append) Paper Spaces tothe Layout Book of the Project.

In the Merge content of Model Space into current View, a dialog box is displayed to set options of how to import the DWG plan. Generally when choosing this option, the intent is to retain the coordinates (World Coordinates in AutoCAD) so the insertion point is set to 0,0 and the scale to 1, and rotation also to 0, and more importantly the anchor point to the Drawing’s own origin.

There are other options to consider such as what story to place the DWG on, and import as a GDL object.

In the Append Paper Space(s) to Layout Book option, you can choose how blocks in the DWG file are translated into ArchiCAD and whether or not convert AutoCAD Labels into labels.

The DXD-DWG translator is out of the scope of this blog post, and will be treated in a dedicated one.

This option is ideal for two situations for Importing CAD plans to integrate in your project and you won't have to edit or model using them , especially the Append Paper Space(s) to Layout Book (provided the layout in the paper spaces is well done in the AutoCAD file). Also it’s a goof fit for Importing a DWG and retaining the coordinates system.

It’s important to have in mind the drawing units used in the CAD file.

Attach Xref

External reference files (XREF) are similar to Hotlinked Modules, the difference is that they are DXF or DWG files and not ARCHICAD files.

This method allows you to save disk space. By attaching a DWG or DXF file to your Floor Plan, the file is loaded into the Project and displayed, using the settings of the DXF/DWG Translator you have selected.

To attach an Xref into the current ARCHICAD Project, use:

File > External Drawing > Attach Xref.

You can browse for a file in your disk or fro; BIMcloud.

If you want all levels of nesting displayed in the Project file, choose Attachment in the Reference Type, otherwise choose Overlay.

All of the other options are similar to the ones in DXF-DWG Merge dialog box, and since the xref method is also a good fit to retain coordinates, you will have to uncheck Specify On-Screen for the Insertion Point.

Snapping to all the drawing elements within the XREF is available.

This method is ideal for elements that are common to several kinds of drawings within a Project like topographic surveys. If you have a file containing this data, you can attach it to other drawings that can use the geometric information contained in the XREF file without the Project file actually having to contain the data. 

Also, if the source of the data in the external reference (the DWG or DXF) is changed, then these changes can be updated immediately so the latest data is always available.

Place an external drawing

To place an external drawing into the current ARCHICAD Project, use:

File > External Drawing > Place External Drawing (or Place External Drawing from BIMcloud).

The Place Drawing dialog box is displayed:

The option Store Path as Relative to Project provides the ability to work on a server and move the project folder back and forth from the server without losing the link to the CAD file.

After you choose the file, a Drawing Unit dialog box is displayed to choose the unit used in the CAD file.

When you click on Place, you are prompted to enter Anchor Point of Drawing that is basically the center of the drawing.

In the case of a multiple page PDF, you can select the page you want to place.

Note: if the PDF is made with AutoCAD (or other vector drawing software), snapping will be available.

The drawing you just placed is stored in the project as a Drawing that you can access its settings.

You can set a custom ID to the drawing, modify its name and more importantly set the Update Type.

If you choose to update the type manually, you will have to update through the Drawing Manager or by right clicking on it.

Other options to take in consideration are:

• Pen Set: choose By source file, or one of the pen sets in the current project.
• Colors: original colors, grayscale or black & white
• On Screen Preview precision
• Drawing’s own Layers: you can show or hide layers.

In the Frame section, you can choose a Manually resized frame and crop the drawing.

You can also add a printable border.

This method gives you the possibility to explode into the current view (depending on the work and editing you’re doing) by right clicking on the drawing.

You can then choose whether or not to keep original elements, and how the layers are converted.
Using Drawing’s Layer means that all the objects will have the same layer the drawing’s had when you placed it. You can choose to Import Embedded Layers.

It’s important to know that one you explode the drawing, you won’t be able to update it if the origin CAD file is edited, that's why there's an option tp whether or not to Keep Original Elements After Exploding.

Also by right clicking on the drawing, you can link it to another file.

This method is ideal for drawings to import into the worksheets for further modeling, or details that will be exploded to be edited.


These were the options offered by ArchiCAD to import CAD plans (and even PDFs). There is not a perfect option, just the one that fits the project you’re working on the most.

And you fellow ArchiCAD users, what are your practicies when working with CAD plans ? Which method you use the most ?

I would like to know about your thougts about this subject in the comments.