Stairs, Ramps, and Railings - Autodesk Revit Architecture 2015 Essentials - page 107

FiGure 4.21 First sketch and Tread/Stringer Offset
4. Click Finish Edit Mode to complete the railing.
5. Create another railing using the same steps but for the opposite
outside three stringers. Instead of using 2 ″ (50 mm) for the Tread/
Stringer Offset use -2 ″ ( -50 mm) (Figure 4.22).
FiGure 4.22 Second sketch and Tread/Stringer Offset