The side room is 10x12' - it is going to be the "office" - computer, etc in there ... along with books and lots of airplane pics.
It actually does have a bathroom, but it is so old that there is no water line out there any more. The soil pipe is still there. I took the toilet out and double insulated that room and am going to use it as a compressor room. Also has an attic accessed via a large stairway for storage.
The building is probably >60 years old - so old that the lumber used to build it is not standard dimensions. It is VERY solid, very dry and well built. Can't wait to get the RV over there!