how to make a model of interior and exterior of a house
2 Answers

1.-In Auto Cad = 'Format'- thickness and elevation (.e.g.- wall thickness 6" and elevation 8' high
2. Use 'Polysolid' enter thickness and height.
3. Use 'Box' command with thickness and height. Use rectangles or boxes to place walls and doors and use subtract command from the walls.
All of these are in the "view" 3d modeling under tools - workstations