Just turn the view to wireframe and trace over the stair in the background with drafted hidden lines. If you lock each individual drafting line to the risers and treads they'll move with the stair. This not be necessary though. Turn your view back to hidden line when you're done.
Thanks for your reply.
Is this the only way? It is a lot of work, because there is also a railing on the stairs.
You can also use the Linework tool in the same manner. Change to wireframe, then with the line style you want selected in the linework too, click away. When you switch back to hidden line or whatever other mode, those lines will show. This has the advantage of (mostly) updating if you change the stair.
I would use the Show Hidden Lines tool (found on the Graphics panel of the View tab).
Change view to wireframe. Select Show Hidden Lines, select wall that is obscuring stair/ handrail, then select the stair/ handrail. Change view back to hidden lines. This has all the advantages of what others mentioned in earlier posts; however, you do not have to make all the individual picks.
Jason Coe, Design Technology Manager
Ashley McGraw Architects
Syracuse, New York
"Nothing happens by chance and coincidence is when God wishes to remain anonymous"
Thanks for the reply's:
I already tried to use the hidden lines tool, it works fine for the railing, but not for the stair.