In the properties dialog box for the view you want to see the overhang lines in set the underlay drop down to be the level on which the roof was created.
How to turn on overhaed line of roof in revit.
You can even underlay the same level as the view to select a ceiling or beams or other elements that are not shown in the view.
Now the next step is to select the linework tool from the modify tab view panel.
With this line style selected all i need to do is click on each line that i want to apply this style to which is all the lines that make up the perimeter of the roof boundary.
If level 2 has a roof you can select the roof in the plan view and then modify it.
Let s go ahead and select the overhead line style.
Select each boundary line and set the value in properties or in option bar.
Use pick walls if you want the roof to automatically adjust when walls are moved.
Overhead beams as dashed lines on floor plan.
You can use the overhead line style for tracing underlays or define your own line style.
5 activate overhang on picked walls roofs.
Then select the line style you want to represent the roof overhang in the view.
You can set an overhang on roofs created with pick walls.