I want to create a room with a cathedral ceiling. How do I do this?
When a room's ceiling is pitched rather than flat, it is referred to as either a cathedral or vaulted ceiling. Cathedral ceilings are the same pitch as the roof and are typically produced by enclosing the bottoms of the roof rafters with a ceiling material.
Vaulted ceilings, while similar, do not share the same pitch as the roof, and are often framed using scissor trusses. If you are interested in a Vaulted Ceiling rather than a cathedral please review this article on the subject: KB-00068 - Creating a Vaulted Ceiling and Scissor Trusses
To create a cathedral ceiling
Open an existing Chief Architect plan in which you would like to create a cathedral ceiling.
Click the Select Objects tool, then click in an empty space of a room to select it.
Note: In order for this method to work, the selected room must have a roof built directly above it, rather than a living space on the floor above.
With the room selected, click the Open Object edit button, and on the Structure panel of the Room Specification dialog, uncheck Ceiling Over This Room, then click OK.
Select 3D> Create Perspective View> Full Camera then click and drag inside the room to view the result.