As an architectural hobbyist, i design a lot of houses that have sunken rooms, esp. with rounded step-downs. I love this program but this of course is a limitation.

I shouldn't have to create a new level that's only 6 or 12 inches tall for a sunken room. Workarounds are great if there's no other way.
I think though that if you give rooms another attribute - "floor elevation" - this might solve the problem more easily (well... not more easily for the programmer [:D] ).

However, this won't completely help my problem. I could create a "room" for the sunken part of a den, but often the steps are curved, so i would also need to have the option to define curves for room boundaries.

I hope this request makes your FREE application even better than what it is. I found it after window-shopping at the "Sourceforge Mall" [:D] and i had been using Gmax (which actually has TOO many features for my purposes). I've only sat down for one session withe SH3D after thoroughly reading the documentation, and there are a few things that can be improved but overall it's an absolute delight! [;)]