The Platform Hole tool can be used to create a hole in a ceiling plane. Add a molding and a manual ceiling plane to finish it off.
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.
You can easily create a custom curved ceiling for your structure using a manually drawn ceiling plane and using the Curved Roof options.
You can model a wide variety of ceiling finishes and furring strips using the Ceiling Finish Definition dialog and the framing tools.
Like other kinds of lowered or dropped ceilings, you can create a suspended ceiling with ceiling tiles by setting up a custom Ceiling Finish Definition.
One way to create a coffered or trey ceiling is to use polyline solids and using the option for Hole in Polyline Solid.
When the Default checkbox, or letter (D), is present in text fields in a specification dialog, Chief Architect will automatically apply the default value.