Each large room that had two doors were both numbered with the same number. That is to say, Room 7 has two doors. Each door was numbered on the wall with a number 7. Room 8 is large and has two doors that are both numbered 8. The church's numbering system did not make sense to me on the day I visited and it doesn't make sense to me now.
Many doors did not have a number. You can see, prior to SP rounding the corner that the interior wooden door in the SW corner is not numbered. The rooms SP tries to open are not numbered in the Western Corridor.
In the beginning, in the W hallway, I suspected the door with the glass insert to be a closet since SP exits with a tool in SPs hand. It may be a small room at the back of the Sanctuary [where equipment for cctv or electronic purposes is located, for an example]. Other people think the door was opened but a different and shorter SP exits. SP makes a feeble attempt to breach the next door. Neither of those doors are numbered.
Also, I reviewed the cctv and noticed SP shines his light toward the camera and not on the number 14. You can see the position of the number 14 on the right hand side of the recessed area.
According to Jethro's theory of the attack location, I'm wondering why Missy would walk down the S hallway upon entering the Church. The Library is appx half as deep as the other rooms. Hence, behind the Library there is a hallway or some other small rooms that are not very deep. The Library is not numbered.
The quibble over Room 15 is one I cannot reconcile. At the visit, it made no sense to me to number the doors entering the restrooms. Even if the Church removed the medium blue alcove walls, the Restrooms cannot be moved and both would remain on the Western wall of the Church. I've stated it once, but in Mr. Taylor's image of the SW corner shows the men's room would jut out into the patio space.