CAD to walls; no floor no ceiling

[Dekade]

In HD Pro 9 I did an import of a .dxf file from an architect. Then I did the "CAD to Walls" maneuver under the CAD drop down menu.

After doing so there is no floor and no ceiling. What is the best means to add the floors and ceilings. I just want flat ones. All I am doing here is showing a customer what the inside of their rooms will look like. This is not a full fledged foundation to roof project.

Finally is there any way to manually make a wall thicker or thinner by handle dragging versus "Open Object"? again.

Once I'm over these few humps then I can get along just fine on my own. But don't count on that as cardinal truth. I'll probably be back here again soon.