Have concerns regarding electrical wiring in an 100 year old farm building (i.e. barn) who's hayloft is being converted to an occasional play/sleeping area for children. A workshop/garage has been added to the barn and the plan is to extend the electrical wiring (romex) from the workshop to the hayloft area for lighting etc. The wiring from the workshop to the hayloft area will have 10' to 20' of electrical wire that run along old barn support beams. My questions are: 1. Is romex wiring suitable for this application and 2. Does the wiring in the hayloft area need to be enclosed in metal conduit to prevent damage from animals (mice, chipmunks, raccoons) that get into the barn during non-use?

How old is the wiring in the barn and loft and what is the ampacity? Protected by Breaker, fuse? Appropriate Life safety code? -"occasional play/sleeping area for children". How do you protect the existing wire and have animals eaten it before? It is easier to run single conductor wire through conduit rather than Romex although for a straight 10-20" probably won't make much difference. I would be very concerned for children sleeping in a barn loft unless there were 2 means of egress.

What out here. You are messing with the "use" definition. By definition, a barn is not habitable. When you chane it to :habitable space the code requirements change.

Take a moment and check with your local inspectors exatly what is required for this change/