1) Start by going to Graphisoft’s page to download the ArchiCAD Connection for Revit, the plugin supports Revit 2015 (2) or previous versions of Revit (3)

2) Run the installer to add the plugin to Revit. 

3) From within ArchiCAD, export a .IFC file using the settings as shown below. 

4) Start a new Revit project and go to the Add-Ins Tab (1) and then click on Improved IFC Import (2) 

5) Navigate to your .IFC export file and click open (Revit may prompt to unjoin elements, this is okay, click unjoin and continue). A prompt will displaying showing if the import was successful, click OK and view the model.

6) The model should now be comprised of Revit system family elements of Walls, Roofs, Floors, Windows and Curtain Walls, which you can use RTA to run analysis of your building or upload the model to the Web App for further investigation.