There are some extensions in Revit that can be used to generate the layout roof members. These roof members may be exported as DWG a consultant working in AutoCAD were to use them as a basis to perform detail design from.

Generate a roof by footprint. Select this roof and then use one of the extensions (Rafter Framing) to generate roof members.

<Extensions><Model><Rafter Framing>

As can be seen there are many settings available for Rafters, Hips/Valleys, Ridges, Collars and Purlins.

Once one has selected one’s settings to one’s choosing (I have chosen the default settings), the software generates the required model elements. Here the generic roof is hidden in the current view.

When the roof has only one ridge, then the Roof Trusses Extension can be utilized to generate the model elements. Wall Plates, Ridge Trusses and Roof Ends settings are available.

The resultant model elements can be seen below (the roof has again been hidden in this view).

These model elements may be exported to DWG if required. <Application Menu><CAD Formats><DWG>

Generally speaking, someone downstream may which to work with the model objects in Solid form (as opposed to polymeshes), and for this reason, among the many settings one may choose for DWG export, choose to export solids in ACIS format.

Choose also not to “Export views on sheets and links as external references”. If one does not, then one will first have to bind the external reference in AutoCAD before being able to work with it.

The individual model elements are written to DWG as block references, but once exploded these now appear as solid objects that can readily be edited. Seen below is the solid object (model element) in AutoCAD.