Configuring the room design

1. Modify the room shape.
   For example to add an angle to an outer wall:
   1. Select the corner tool in the toolbar.
      The cursor icon now looks like this when you move it into the layout:
   2. Click on a wall where you want to add the 2 new corners that will define where a new wall will begin and end.
   3. Select the resize tool in the toolbar.
      The cursor icon changes into a double-headed arrow when you move it over a wall in the layout.

   4. Click the wall between the dots and drag the new wall into position.

2. Add inner walls or cages.
   For example to add a new inner wall: 

   1. Select the draw wall tool in the toolbar. 
      The cursor icon now looks like a plus and coordinate guides appear. 

   2. Click and drag in the layout where you want the new wall to be.
      A new wall of the default type now appears in the layout. 
   3. If you want to change the wall type, right-click the wall and select Set Wall Preferences, then select a predefined standard wall type or select Properties, and set the width and type (mesh, solid, glass).

3. Add room fixtures, such as doors, windows, and walkways. 

4. If the room has a row layout, select the Generate Rows icon in the toolbar and follow the instructions in the wizard.

5. If the tile grid does not match the actual physical environment, select the pan tile tool in the toolbar , and drag the tile grid around until the tiles are located properly in the floor layout.

See here for details about setting preferences relevant to the room design.