Select each boundary line and set the value in properties or in option bar.
How to turn on overhaed line of roof in revit.
You can use the overhead line style for tracing underlays or define your own line style.
Then select the line style you want to represent the roof overhang in the view.
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.
Overhead beams as dashed lines on floor plan.
Now the next step is to select the linework tool from the modify tab view panel.
You can set an overhang on roofs created with pick walls.
If level 2 has a roof you can select the roof in the plan view and then modify it.
Once you select this tool you get a choice of line styles from a drop down menu.
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.
Revit plan views show overhead eg stair parts walkways in floor plan view view properties turn on underlayfor the level where the feature is set say an intermediate landing or gantry in view props set underlay orientation to rcp.
5 activate overhang on picked walls roofs.
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.