Ventilation vs draft

Lots of opinions on this and I'm glad you told where you live because that will have a bearing.
Draft vs. ventilation is a tough balance but IMO adequate ventilation trumps any issue of draftiness.
Some people's chickens roost in trees. No protection from drafts there.
I wouldn't want chickens wet and drafty nor extremely cold and drafty but I have big openings in my buildings with no problems.
If you are always windy, openings on only one wall usually solve the problem.

 

You can end up having wind blowing through a coop, especially if you have openings lined up across from each other in the direction the wind is blowing. You can set your coop up so you don't do that in the winter. Also, hot air rises and cold air sinks. Air will come in one opening and exit another. The warm air exiting a higher opening will draw cooler air in through another opening.

As long as you don't have the roost in the path between openings, you should be good. I also like at least part of the floor area to not have a draft in the winter, either. I don't mind if it's drafty in the area near pop hole doorway. This is just going to happen when it's open during the day. They can just move to another location in the coop if it's bothering them.

Unless it's cold weather I don't worry about drafts and in hot weather, a breeze from the open windows can help them deal with the heat. Since you're in Texas, I'd want to plan for a lot of ventilation in the summer heat. I have a lot of adjustable ventilation in my coop. In the summer, it's very open.

 

I live in Texas & I have one 4 sided coop & two three sided coops. I love the three sided coops for this area there great for the extreme heat we have here. My only concern in the winter is to keep the cold wind from blowing on them. I just block the wind with clear plastic. The cold doesn't seem to bother them. Last winter it was 19 in the coop & they were fine. I did however block the pop door off for a few days the wind was blowing straight through the pop door & the chickens really didn't want to leave the coop anyway.

 

This might help: https://www.backyardchickens.com/forum/viewtopic.php?id=163417

I agree, in this warmer climate, a 4 sided coop is just a place to try to keep cool much of the year; chickens tolerate cold much better than heat, and I would go with 3 sides and a roof only. In a windy area, they will get accustomed to some air movement most all the time. A draft refers to a cold stream blowing right on them. If your 3 sided shelter faces east (usually) then this should not be a problem. In hot weather, a "draft" becomes a welcome breeze.

 

Ventilation is important, winter and summer. In Texas, your summers will be very important. Chickens normally handle cold much better than hot. But you still need good ventilation in the winter to get rid of excess moisture and ammonia build-up.

The way I get good ventilation is to have the permanent openings at the top of the coop, well above the roosts. It depends on how your coop is built, but I suggest having overhangs where you can to keep the rain out and have openings under those. Cover them with hardware cloth to keep predators from climbing in. Roof vents and such can also work, unless they get covered in snow. A breeze blowing above the chickens while they are roosting does not bother me. It's just a breeze hitting them that can cause a problem.

During the hot weather, have a window or two or some other vent you can close in winter, also covered with hardware cloth to keep predators out. Even a couple where they get a cross breeze won't hurt in the summer. Wind chill is only a factor when the weather is cold.

I don't know where you are in Texas. There is a difference in Corpus and Amarillo. Many people along the Gulf Coast use those three sided coops 7L is talking about year round and some of those places will see below freezing. Just put the roost in where it is pretty well protected from direct breezes.

Growing up, we had some chickens that slept in trees in pretty cold weather. These were pretty dense trees in a protected valley, so maybe the breeze was not hitting them as much as you might think, but yes, chickens can handle cold better than heat.

 

Here's our chicken barn. In the heat of summer, I can open all 4 doors, effectively making it a three wall structure.

 

Quote:Some people have a way of giving good advice in much fewer words than I can.
I think it's call concise.