Working with my architect on the ceiling for our formal Living Room. The room is 22x19 and the ceiling is 15 feet high. The ceiling will be coffered with each coffer being approximately 3'4" on a side. The inside of the coffers will have crown molding and LED cove lighting.

I am trying to determine the proper depth of the coffers. I am looking for the Goldilocks depth - not too shallow and not too deep, but deep enough to have some drama. The depth is currently spec'd at 8". Does that seem right? Wondering if 10" or 12" might be more appropriate.

Thanks.