The application will arrange the model into Facades based on orientation and planes. There may be several South facing Facades for instance if they are on different planes. Within these Facades are Surfaces, defined by Levels and Internal Walls. Each time there is an internal wall, a new Surface will be assigned for that Space/Room.
The ‘Spatial Elements‘ option (for Detailed models) will assign separate Surfaces for each Curtain Wall. ‘Building Elements‘ will create larger Surfaces with several Curtain Walls within.