I had this old fiber glass greenhouse that i decided to turn into my chicken house instead of buying or building one (I mean free is always better right?). It has a screen door on the front and a window on the back to provide great ventilation, especially in the summer (I live in Oklahoma so on days it is 109*F outside it is probably double that inside), but i do plan on adding a greenhouse fan to suck out hot air to provide additional cooling. It is still a work in progress to perfect and complete, but here is what i have done so far:
1. All screen was replaced with wire to keep the predators out and the chickens in, since I literally watch a small bird fly through it with out any struggle due to being so old and dry rotted.
2. I very generously sprinkled the floor with diatomaceous earth due to a fire ant infestation, which after a few applications they disappeared and have not been back since.
3. Removed shelving leaving only the support bars and placing in a nest box made out of an old bed wooden bed framed. I have since divided the house into two parts due to my three roosters were overly harassing the hens who are not quit ready to breed as are the rooster. I have provided proper nesting and roosting in both parts of the house as well as a small door for the roosters to be able to enter/exit to the run as needed.
4. Fenced in a run to keep them all contained, yet separated, by using cheap electric fence post's and chicken wire, apprx. 4 - 5 ft tall. But i do plan on to construct a completely enclosed run (sides and top) using chicken wire and 2x4's since i have started noticing hawks circling above. I also placed a metal frame pergola in front of the run to use both as solid structure to attache the fencing too as well as a shady spot for sunny weather and a dry spot for rainy weather.
5. Before adding the chickens i water sealed everything that was wood to help it last longer. I have also found that it makes it easier to clean any poop off.
Here are pictures as of 01/02/2019. Sorry for the bad picture quality. I have a cheep temporary phone I am using since I left my good one in the rain, you guessed it, chilling with my chickens haha.