@Anonymous
Well, Site Designer was terrible to begin with, and it wasn't from "Autodesk"...it was an add-in developed by someone else that Autodesk bought and made it free to subscription users.
And I have nothing against the topo tool though...I've done some pretty awesome site plans utilizing the topo, it's just a matter of not trying to use just one. I've had some sites where I used 20 different topo objects as it was a large and lots of grade changes and daylight basements for buildings. It's just that my sections looked terrible as topography isn't that great when cut and I had to use fill patterns to make by sections pop.
But yeah, you can do something like you are showing in your pic with a roof.... the roof works the same way as the topo, add points at the heights you need them to be.