Everyone has seen an email hit their inbox with attachments in file formats they’ve never heard of. While I can’t promise to explain the non-BIM formats, I would like to review a couple common formats we see pretty often in the BIM world. Here are the top five BIM file formats we see the most and what you can do with them:

1. DWG – This format is almost universally accepted by most model viewing/authoring programs. Also commonly referred to as CAD files, this might be the most ubiquitous digital file format in the AEC industry (and beyond). Anytime someone mentions “layers,” they are likely referring to a DWG file. Generally, these files are editable in any CAD-based program such as Autodesk AutoCAD, Graphisoft ArchiCAD, and Bentley MicroStation.

A common misconception with DWG files is that they only contain 2D information. Although that is typically true, DWG files can absolutely contain 3D objects as either basic planes or full components (known as “blocks”).

2. DXF – A very close cousin to the DWG, DXFs can be a little larger in file size but are also layer-based and a very commonly accepted format in most platforms.

3. IFC – These are arguably the most information-rich BIM files out there and can be opened by a number or programs including Autodesk Revit and Navisworks. These are similar to PDFs in that they are not meant to be edited and are a read-only format.

4. RVT – This is Autodesk’s proprietary format for Revit files. These can vary significantly in size depending on the level of development. They can only be opened in Revit.

5. NWD – This is Autodesk’s proprietary format for Navisworks files. NWD files are also read-only, although you may be able to save them under a new name and edit from there if the file was saved with that option enabled. These can only be open in Navisworks Freedom or Navisworks Manage.

There’s a seemingly endless supply of file formats out there and this is just a start. What are some of the most unusual BIM file formats you’ve seen? Share your comments below. For a more extensive list of BIM file formats, see this handy ArchiCAD wiki page.

Zack Creach is a senior engineer for Holder Construction in Atlanta.