Welcome to the forum!
We're up in North Texas, so we're kinda in the same boat, climate wise. The chickens we keep are tiny bantams who are our pets, so I tend to be overly solicitous about their comfort during cold weather.
A three sided coop can be retrofitted with a tarp or removeable panel on the fourth wall for winter. A very experienced poultry keeping friend of ours in the neighborhood uses open sided chain link dog kennels with metal roofs. He tarps the sides to block the wind in winter weather. It works fine, but this year he did have trouble with some of his smallest bantams during the below freezing week we all endured. Standard size chickens manage even below freezing weather fine as long as they have a dry, draft free but adequately ventilated shelter.
I think you really need to worry more about summer, especially if you pick standard breed chickens. Try to pick breeds that are known for heat tolerance. I built a completely open sided roofed coop but stupidly put it someplace in our yard where it gets afternoon summer sun. Big mistake. Even with the open sides, up under the roof (where the chickens roost) gets terribly hot and stays that way even after sundown. So site your coop where it gets the most natural shade. That's my no. 1 bit of advice.
Our final (really!) coop is a conventional closed sided one, but it has plenty of ventilation. It's also sited properly in our yard so it stays shaded. And it's insulated, which helps keep it cool in summer and retain the supplemental heat that I add during freezing weather in the winter. I used that radiant roof sheathing, too, because the coop does get some sun in the mornings. Last August the coop got no hotter inside than the ambient outdoor temperature, which is as good as it's gonna get.
Take a look at my BYC page for more specifics about my coops if you're interested.
Even heat tolerant chickens appreciate some help to manage our weather. You can put out shallow pans of water for them to stand in. Plastic plant saucers work well for this. Their feet, combs and wattles are the only parts of their bodies that don't have down insulation and it's through these body areas that their blood can be cooled. They also hold their wings away from their bodies and pant.
I freeze a jug of water and then put it out in the run for the chickens to stand around, and on the hottest days I run a small fan next to the run, blowing over the ice. I put ice in the waterer sometimes too. The panting makes them dehydrate and they won't drink as much water if it's warm or hot.