SimLab Composer is not a 3D design application, despite that it includes basic design elements, allowing the user to create special elements for completing or customizing the scene without reverting to a 3D design application.
Design elements in SimLab Composer include:
The following tutorial shows how the user can use some of the design elements in SimLab Composer to complete the design of a room scene, and how to add doors and windows to a closed wall.