My husband (poor guy) just finished our new chicken coop a few hours ago after working on it for 2 full weekends. Our problem was 3 fold..... rats, goats and Florida weather! We wanted to install a coop that would fit inside our goat pen (had extra space there that was safe away from dogs), but the problem was that inside the goat pen we have rats! Plus the goats like the ram everything AND with rain, wind and extreme summer heat we had to do a lot of research before making a final decision. My new baby chicks lived 5 weeks in a ferret cage on my dining room table until we got their permanent home finished, yippee, not a better day to move into your new Easter Egg chicken coop than Easter Day! I was told my chickens are Araucana's but suspect they are Americanas since they now have tails and no funny face feathers. But they do have very green feet! So I guess they are mutt chicks but I have enjoyed every day with them since I brought them home. So smart and people friendly, they were calling for me this evening when the sun was going down, they were scared in their new surroundings. So after 4 trips out there to reassure them, they finally settled down in their new home.
We ended up purchasing the plans on this site from Dennis on Small Playhouse Coop, $35 well spent for online video and detailed plans. But we took his plans and revised them to accommodate our needs (and budget), which included 2x4's (pressure treated) vs 1x3's, 1/2 inch wire vs 1 inch wire, plywood vs cedar, rubber roof panels vs metal roof panels, added wire from frame to frame underneath the roof, and added a complete wire floor to keep rats from burrying underneath it. In addition we made it 3 ft wide vs 4 ft wide (stock width of wire), shortened the height a tad so the roof didn't show over the goat pen privacy fence, and to make up for lost space in the nesting area on width we brought it out in depth by one foot. We are also adding a resting ledge in front of the nesting box since my chicks seem to enjoy just hanging out together on ledges.
But to respond to your concern about the rats, that was our biggest problem too, so we added a framed out bottom completely covered in wire. We buried that in the sand/dirt about 3-4 inches so the chicks would still have pecking/scratching depth and bugs/worms could still surface. So the entire coop is now surrounded by wire, even the roof panels have rat proof wire underneath. You have to use the 1/2 inch wire, not 1 inch or the rats will squeeze right through. And every frame has to be wire to wire, we used about 1300 staples in this project. And the roof panels have to be screwed in and sealed so rats can't get underneath. It would certainly be easier to kill the rats, but with our 6 dogs, 2 goats, 11 cats and more, we can't chance using any kind of poison on our property.
You are welcome to write me if you have any other questions or wish to see photos, my husband can fill you in or I can send photos. Our total cost for this neat chick abode is currently about $250 and still counting. Send email to CrittersInc@aol.com. Good luck!