Do you need to add electrical information to a floor plan?
You could add the electrical symbols directly to the floor plan. However, you're diagram will quickly become too cumbersome to deal with. You might have a hard time modifying anything on the floor plan with the new symbols in the way.
You could create a brand new document with the electrical symbols, but then you'd have to recreate your floor plan and maintain the same floor plan diagram in two places.
It's cleaner to treat the electrical symbols as a separate group and just layer them on top of the existing floor plan you already created.
Once your floor plan and electrical plan are separated into layers you can see and modify them independently.
Using layers, you can hide the electrical information when you don't need to see it.
You can also edit the electrical plan independently from the floor plan. You won't accidently click or modify parts of the diagram you don't need to.
Learn more about using layers in SmartDraw here.