Elevation of section you can select a reference plane to sketch your profile on as long as you have a named one in your model.
Roof by extrusion.
We also need to use a refrence plane upopn which we can sketch the side profile for our extrusion.
Specify the work plane.
Display an elevation 3d or section view.
The highest level in the project is selected by default.
In the roof reference level and offset dialog select a value for level.
Key points the roof by extrusion tool is used to create wave form type roofs you create a sketch of the upper profile of your roof in a side view i e.
Within revit the roof by extrusuion tool is used in an elevatation or section view as opposed to the roof by footprint tool which is used in a plan view.
So first of all let s go ahead and create our reference plan.