The Industry Foundation Classes IFC specification is a neutral data format to describe, exchange and share information typically used within the building and facility management industry sector. IFC is the international standard for openBIM
- source

Exports to the IFC format can be done in an AutoCAD version that supports conversion (usually AutoCAD Architecture). This article is a step by step guide that will cover how the export is done. First, the model must be generated in an empty drawing. Create one under the category 3D in the project browser, as shown below.

Figure 1: New 3D drawing

Open the empty drawing and generate the elements that will be included in the export by using the generate plan command. Configure your selection of elements and be sure to select the AutoCAD solid (IFC) option found under setup. This allows export to the IFC format.

Figure 2: Generate the elements as IFC-compatible solids 

Chose what information about the elements to include in the export. This is done through the "add property set" command found under the "base" tab in AutoCAD.

Figure 3: Add property set...

Select the options that are interesting to include, and then click ok to close the dialog. It is compelled to actually press "ok" to include entries in the export, even if you do not make any changes to the list.

Figure 4: Select properties to include in the property set

Make the export from AutoCAD file menu as shown in the image below. 

Figure 4: AutoCAD export to IFC

Enter a project number and change any other information. Then proceed by pressing export.

Figure 6: AutoCAD export to IFC dialog

Element color

The elements in the export can be colored in two different ways, both of which depend on how the variable SOLIDCOLORBYMATERIAL is configured. Either, the elements get the color based on AutoCAD's layer 0, which by default is black. Or, the elements will be colored based on its material color. Materials are configured in Standard Admin with an exact color (RGB value).

With the variable value set to 0 (turned off) the model will inherit the color of layer 0 - black.

Figure 7: IFC model colored by layer 0

With the variable value set to 1 (turned on), the elements/components will inherit the color of its material. In the example below the walls have a grey color from the concrete and the CIMs have a slightly darker gray which makes them visible when the model is viewed as somewhat transparent.  

Figure 8: IFC model colored by material color (true color)

Access IMPACT data

In this example, I've opened up an IFC model exported from IMPACT in Solibri Model Viewer. I've included some data in the export according to one of the chapters above and it appears under the IMPACT tabs, as shown in the image below. There is the information I chose to include like geometry, weight, and element mark.

Figure 9: Accessible IMPACT data