Looks like you're in my zone. I'm in North Alabama, USA. You've got about 275 sq feet of space. [EDIT: I read feet when you stated yards. Sorry about that. Rules of thumb still work, so I'll leave the rest of my comment, just note that you have vast amounts of space more than what I'm talking about.] 275 sq feet is enough space for about 18 chickens, if you keep them strictly in a covered run using that entire area and no coop. I've found that if I only have a covered run, birds need at least 15 sq ft of space per bird, otherwise I have pecking issues, and stress responses from the birds. I have less space per chicken when raising chicks, but I make sure to reduce the number of chickens to 15 sq ft per bird or more before freezing winter weather, when stress is highest.
Or, if you build a coop connected to that space you've outlined, and give them at least 5 sq feet floorspace per bird in the coop, and use that entire area as an outdoor run, rule of thumb says 10 sq ft per chicken in the run, so you could house up to about 25 chickens. Your coop would need to have at least 125 square feet for 25 chickens, not counting areas they can't walk in, like where feeders and waterers are, and nesting boxes.
I don't use a coop, because it's not needed IMO. I fully protect my covered run with hardware cloth including a 3 ft apron because we get ALL the predators, and I can't afford to have ANY losses (everyone would cry!).
I did the calculations, and built an 8' x 10' metal shed next to my covered run and then decided to use it as a shed, not a coop, because due to the hot and humid weather and amount of ventilation needed, I'd have had to remove the entire top third of the building and replace it with hardware cloth. And then build larger overhangs to protect from rain. I was a bit worried about structural integrity of the metal shed. I'd have had to reinforce so much I should've just built out of wood from the beginning, but this was when wood was super expensive during covid.
Make sure your birds get plenty of shade and ventilation in the coop and run always, but especially the middle of summer.
For the few months of winter that we get, I put plastic up on the outside of the covered runs to reduce the wind speed for those few weeks of below freezing days. No supplemental heat needed. I've had a few roosters with 2-3" tall points on single combs get frostbite, but that's it for weather issues. All the birds with shorter or pea combs and the hens with single combs were all fine.
My 250 sq ft greenhouse frame coop (10"x25") and 150 sq ft hoop (10'x15') coop with attached tarps have stood up to tornadoes for 3-4 years now, whatever snow we've gotten (I think 6+ inches one year - I go out twice a day and knock the snow off) and a rainburst/flood (Massive rain and 1-2 ft of flowing water for 24 hrs), with no issues. My 300 square ft chain link dog run enclosure with slanted roof did not faire so well in the flood - bad roof design on my part. All of my coops are under trees, so they get moderate shade all day, and a few patches of sun in the morning and afternoon.
Here are some pictures of what worked for me.
I replaced my pallet perch with a poop board perch, and am really loving it - so much easier to clean! Also, you can see summer and winter setup for my greenhouse frame coop. I don't have any super good pics of the hoop coop, but included one with a few roosters in it. The hoop coop has doors on both ends and a central support, while the greenhouse frame coop has a door on one end and didn't need a central support. Had to use re-bar to pin the bottom frame for the hoop coop in place to keep the bend in the cattle panels. The hoop coop IMO was a harder build, and cost about as much as the greenhouse frame coop once all was done, because it required more support structure, and didn't give as much floor space. If I had to do it again, I'd build another greenhouse frame coop. That one worked really well.
Tarps are flared out to catch the breeze, especially important in summer.
