Spaces that have been created by drawing internal walls can be combined together to by deleting the internal wall between them. To combine spaces click the combine spaces button .

 

Once clicked the internal walls of the zone will be highlighted. To delete an internal wall select it in the drawing palette. To select multiple walls hold the shift button. To finish the action hit enter or right click in the drawing palette.

 

 

Note that the two zones in the navigation tree have been combined to one.