A neighbor moved away and left me his homemade Dog-House. Since my dog "Crockett" lives in the house with me....I modified it ....to become a small chicken coop. It is 4 feet square and just a little higher than that. I also built 2 wooden egg-laying boxes that fit inside it....and installed sliding vents (homemade), and doorway, .... and a heat-lamp that I can use as necessary....(mostly to promote laying during the short days of Winter). It seems adequate for the number of chickens that I have.
I plan to build another Coop from pallet-wood this summer.....to be used for breeding other chickens.
-Bruce ( ReTIRED )