You can add a room within the 'Report Editor'
From the Home dashboard and under the heading 'Operations' select 'All Jobs'
Select your Job from the list and from the Job Details screen select 'Report Editor' from the tabs at the top of the screen.
In the 'Report Editor' select 'Rooms' from the left hand side of the screen.
Under the heading 'Add Room' pick from the 'Select a Room' drop-down list and select from the 'Sections' drop-down list for 'Summary & Inventory' ' Summary only' or 'Inventory only' templates and click 'Add'