I have a building model with a ground floor plan and roof. The floor plan has now changed but the external walls and footprint of the building remains the same. If I delete the existing ground floor plan and import a new floor plan will the application data for the roof remain ? I appreciate that if I delete the existing ground floor then all room information previously defined will be lost but if I retrace and input fabric data will the roof remain in place or do I need to start a new model?