1. Question: What is the difference between a bathroom and a chicken pen or barn?
A. The Mishna Berura 84:3 says if you make a difference in the body of the bathroom to make it not a bathroom then it is permissible to place a mezuzah on the door and to make blessings inside it, as well as to learn and Daven inside it. But without a change in the body of the room, then its name is not uprooted, meaning it is still a bathroom even if not in use any more and cleaned out.
B. But a barn, the Be’ur Halacha (79:7 “Aval”) says, only needs a cleaning of all waste to be able to learn or pray inside it. The Levushei Mordechai says this is also true for a chicken pen.
C. The Torah requires “your camp to be holy” to do Holy matters like making blessings, learning and praying. The question is what’s the difference?
Answer: Since the chicken pen or barn is not set aside specifically for excrement rather it is to guard the chickens and animals, it is just that they also take care of their needs in that place then all you need is to clean it out but as long as the room is considered a bathroom even if it’s not in use it is still not “holy” and a disgrace to do Holy matters in that area. See Dirshu Mishna Berura 83:1 footnote 4. [/exapnd]