We are lucky - all of the old buildings are made of stone (as is the cistern). The walls are very thick and the stone keeps the inside of the buildings cool in the summer despite the Texas heat.
There looks to be a remnant of a full length counter top beneath the "window" and it looks like that someone put chicken wire over the window from the inside at some point but beyond these 2 things, there is nothing else. The "window" is placed so that it is opposite of the summer breeze so I will be looking at some form of additional ventilation (roof line vents?) to create air flow. The building is situated so that it only catches the morning sun. The only other oddity is that the walk-in doorway is unusually narrow - less than 24" wide but a full 6 foot high.
I wish it had initially been set up as a hen house - it would have been nice to have an opening for the birds closer to the ground. I am planning to set up runs similar to Dave's plan but am looking to incorporate the window area as the entrance/exit for the chickens. Any thoughts or suggestions would be most appreciated
The original purpose of this building just has me perplexed. I thought at one time that it may have been a milk cooling shed but the old milking barn is far from the house and this building is in the original house's yard. As the land was thoughtfully laid out, I am sure there was rhyme and reason to this building but I cannot figure it out.
Here's a layout of the building:
