I have a metal plate about 12″ square attached to the outside of my two-story house, about a metre aboce the ground. It appears to be some kind of inspection cover but it is permanently attached to the wall, by some kind of nails. There is no plumbing at this point inside the house, but the waste pipes fromt he upstars shower do run in this area. I am wondering if anyone can tell me what this might be? I looked at the house plans and at about this area there’s a notation that says “plumbing risers” but I don;t know what they are, or if the note actually refers to the plate I’m looking at.