You can transfer BIM models from OpenBuildings Designer into OpenBuildings Energy Simulator.
Choose File > Export > Analysis File Types, to open the Analytical Space Model Explorer dialog:
Here, your current design can be interrogated and checked for validity.
Once you are comfortable with the results, click on the Export button and then click Yes if you would like to open the model at this time.
At this point the handover to OpenBuildings Energy Simulator will take place, with the ASM Energy Settings & Validation dialog opening in front where you can review and/or change settings, accept and close.
The project will then open in a new OpenBuildings Energy Simulator window and you can perform your analysis and modifications as needed.
Note that the process is one-way at this time since there is no framework for bringing OpenBuildings Energy Simulator data back into OpenBuildings Designer.
For more detailed information please consult the manuals on how best to set up your model, available Here.