How do I create a 3d room, i.e. far wall, side wall, & floor with just poser? thanks KUMO

Use your primitives and turn them to create the walls you want.

There is a wall set and some window sets in free stuff. There is a tutorial also here on this site that shows how to do it in Poser. Basically you take a cube primative and scale it down so that it is 2D. Just a square. Then you save the square to your props library. Next you add several of these from your props library offsetting each. The free stuff is a lot better than you'll make yourself unless you have a 3D modeling application. Poser is great for animating and posing but isn't worth a dang as a modeler.

many thanks KUMO

Not made with poser but just shows what you can make in other programs that can model- then import into poser. Any object you use in poser was imported and modeled in a modelling program.

I have several for sale and free room/building constructions kits in variuos styles. But use of primitives is one way to create good looking rooms.