You can export the geometry of the current building model in 3-D DXF format using the Export 3-D DXF model command from the File > Export menu. This opens the 3-D DXF Export dialog:
Choose one of two options:
Note: DesignBuilder DXF output uses surface objects and not lines so be sure to select one of the shaded surface view options in your DXF viewer. Wire frame views will not display the model.
Example 3-D DXF Output - Whole model with details
The above model was created in DesignBuilder, exported in DXF format using the Whole model with details option and Imported into SketchUp where details such as textures, trees and people were added.
Note: when importing DXF files into SketchUp be sure to set the units options on the Open dialog to Metres.