I have a house that has a two-story cathedral ceiling. I was thinking about adding a floor and turning it into new rooms in the house. However, a web page I read said "Vaulted ceilings create no floor space. In fact, they prevent you from ever building upward and into that space."
The author does not further explain this remark. Why would I be unable to build into the space? From a geometrical perspective I could still get 10 foot ceilings in the living room and at least 9-foot ceilings in the upstairs rooms, so there would seem to be no limitation from a headroom perspective.