What part of the plans do you need?
We have a 10 x 18 shed that was used as a pig shelter to start, and calf shed later on in its life.. I covered it in and built a chicken shed out of it. I made a 12 x 18 run in the front covered with chicken wire. Put a roost inside and built nesting boxes to hang on the wall. Have a hanging feeder to keep the mice out, and a metal waterer that sits on top of a heated base to keep the water from freezing. Works exceptionally well.
The big thing, depending on where you are is keeping other critters OUT.
I put 2x4 dog fencing around the bottom. I bent the lower foot and a half, dug down all the way around and put this down, then covered it up. I then attached the chicken wire to it. A LOT of eagles around here, and the fish and game frown on anyone shooting eagles, so I covered the top with chicken wire as well. the 2x4 dog fence I buried is so when that fox/coyote/Coon, Dog or cat comes calling, and tries to dig their way in, the fence foils their attempt because they cant dig through it,and most critters arent smart enough to move AWAY from the chicken wire to find out where it starts.
There are a lot of plans on the internet, but most I have found are more for the urban chicken keeper's back yard. I didnt want to spend that much money, so improvised with what I had. 3 years and still working fine!
