I live in SE Ohio. I do not provide my hens with supplemental heat, just a well insulated coop with plenty of bedding material. BTW, if you are familiar with old fashioned hot frames, the heat is provided by decomposing manure. There is plenty of that in a chicken shed. I'd be very concerned about fire issues with an electric heater in a coop.

OTOH, those red (and sometimes white) bulbs are not just ordinary lights. They are designed to give off heat. I use them in my brooder boxes. You can find similar heat lamps in GB in dog kennels for cold sensitive animals, where it may get cold, but not frigid like the interior state in the U.S.

Is is really so cold in Texas you need supplemental heat for adult chickens? It isn't in Ohio, really with adequate shelter and the right breeds.

Kit, do you mind telling us where in middle south Texas you live (near Dallas, San Antonio, Austin, etc)? I'm in Austin. My girls spent their first winter outdoors last year and everyone did fine with no heat. Of course my girls are what I call 'fluff butts'---heavy breeds with lots of feathers. On two occasions last winter, I brought them into the garage for the night because of very cold weather------no laughing you Northerners! In the winter, I also provide them a flat surface to roost on so they don't have air riding up under those fluffy bottoms.
As for the light thing. I wouldn't. You point out wanting to let the girls have a regular year with no artifical lighting. I feel the same way. We get more than enough eggs to eat and I'd rather mine have a break. If you were really afraid of cold birds, I'd go with the deep layering of shavings that composts itself and warms the coop.
Carla

I live in zone 4... 2 winters ago we had over 2 weeks of temps that never got about 10 degrees F. I gave my hens heat for the ultra cold weather, but normally I didn't give them heat unless it was below 20 degrees F. Being in TX, I don't think you'd need to give them ANY heat. Just my 2 cents having raised chickens in zone 4...aka: too damn cold!

I live just outside Hallettsville, South of Rte 10 well below Austin. Generally we don't go much below 30 deg. but being a new flock mom I think I am a little overprotective.
I did get some frostbite on a couple of my hens combs.
When a Norther blows in from the Great Plains it can really drop into the teens.. My flock consists of heavy breeds with some Ameraucanas thrown in.. I was worried about the heat lamps because of the warnings about UV burns being possible.. I guess I will have more faith in their adaptability now. They have a South facing coop with insulation in the walls but the door has a large gap at the top.. Thanks, for the input!! Kit

This might be a dumb thought, but wouldn't some heavy material tacked over the door to hang over the gap help a little? Maybe canvas or old jeans. I would just make sure the fabric fell several inches below the top of the door and make sure it is pulled to the outside when you are not using the door.

Again, might be a dumb thought, but I think that's what I would do in that situation.

Kay

I have plastic sheeting that covers the top third of the door opening on the inside. It does cut the wind. I think I may follow your suggestion and switch to canvas.. It would be heavier and less likely to let in any stray wind. The gap it only about two inches but on a four foot door that is quite big.. The door is South facing so it doesn't catch the North wind.. Next year we are going to tear down this old building which is held up by termites, wood rot and just plain habit. The new coop will be a insulated metal building with more room. This was here when we bought the place a year and a half ago..
Thanks,
Kit