Riser for home theater

[mweston]

I haven't used the software much, but I searched hard to find a way to build a riser, so that part of the floor is, say, 10" higher than the rest of the room (for the back row of the theater). And I did not find it.

I thought maybe I could build some stairs with only one tread (like just a landing), but I couldn't figure out how to make that happen since the software is too smart for its own good. I could probably take some piece of furniture and distort it, but that won't look right. The only good news is that at least I can create a couch that is 10" off the floor.

Is there something obvious I'm missing? I'm using Interior Designer. Thanks!