I agree a hoop coop would work well, especially in the South. I think there may be a tendency to over protect chickens, they can bear colder weather for a little while without a building. I'm in a colder climate and and I keep the run door open in their house year-round.You do but the hardware cloth is pretty simple and fast. Cover the top with metal for rain protection, shade and secure the top of the hardware cloth. The hard part is framing the ends and making the door. You can cheat and buy an extra cattle panel and cut it down for the back end.
Another advantage is you can move hoop coop easier, allowing you to rotate to new areas and fresh soil.