How big are you making it? What does your terrain look like where you are building it? How do you plan to manage the bedding and poop?
The coop and the run need to stay pretty dry. Occasionally damp or even wet isn’t all that bad but the wetter they stay the more disease-prone they are. A wet coop or run will stink, where a dry one is a lot easier to keep from stinking. To me, keeping a coop and run dry is the most important thing for their health and to reduce smell.
If you are going to raise it, you need access underneath. If it is so close to the ground that chickens can’t get under there, it’s a great place for mice, rats, snakes, or possibly other vermin to set up housekeeping. If chickens can get under there, they will keep the vermin out but it needs to be tall enough for you to be able to retrieve an injured chicken that doesn’t want to be caught or get the eggs if a hen decides to lay under there. The bigger it is the higher it needs to be so you can have that access.
If your terrain is really uneven a raised coop may be easier to build level than one on the ground.
In Round Rock you are not worried about the cold, just the heat. A coop on the ground should not get as cold as a coop in the air due to the ground acting as a thermal mass. A coop in the air might be easier to cool off and can be easier to ventilate if it is in the shade and you have a breeze, but a coop on the ground will have the ground acting as a thermal mass so those usually aren’t too bad either if you add plenty of ventilation. With your open-sided design, I think you’d be OK either way.
With a reasonable sized coop on the ground and if you can keep it dry, you can use a version of the deep litter method and just add bedding when it is needed. If you use a droppings board and don’t crowd your chickens you may only need to clean it out once a year. I’ve gone four years between cleaning out all the bedding in mine and I did not need to then. I just wanted it on my garden. With an elevated coop it gets trickier, especially if it is crowded. Many people paint it or put linoleum or some such cover on the wood to help keep the wood from rotting as easily. Keeping it dry makes a huge difference in how fast a wooden floor rots too. People are successful with a version of the deep litter method with raised coops but it can be a bit more challenging. You may wind up cleaning it out a lot more often than a properly built one on the ground. In either case, any wood that touches the ground needs to be treated or some expensive wood or other material that doesn’t rot.
A raised coop, if it is raised high enough and has a good opening can be a lot of easier to clean, just roll a wheelbarrow under the opening and rake it out versus shoveling it out of a coop on the ground.
If you clean your coop out a lot you can wind up with a lot of bedding. Not only do you have to buy new bedding which costs money, what are you going to do with it? If it doesn’t have a lot of poop mixed with it, it can take a long time to compost. Whether you build it in the air or on the ground, I think how often you need to clean it out is a big consideration.
Either a raised coop or one on the ground can work. I like my big one I can walk into so I can check things out easily plus I think I have to work les to maintain it. But mine is well-ventilated, over-sized for the number of chickens, and stays dry.
