there's oodles of free and spendy software out there that will do this. There's one I know of called '3d Architect', that you can get at places like Wally World, or Best Bye, etc..
There's probably shareware stuff that can do this as well. Check Nonags, shareware.com, sourceforge, etc., and something should turn up..

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)