You can add a “drop-run” to account for a vertical segment when drawing linear (horizontal) takeoff. Typically, you’ll do this to account for extra wiring, piping, or other material necessary to connect a fixture to a horizontal run of something. For example, when wiring electrical outlets, one must account for the vertical run of wire necessary to connect the outlet to the horizontal feed.
Locate the Takeoff Item/Part to which you want to add drop-run.
In the Properties window, simply add a value to the “Length of Drop” field.