Single comb chickens in winter - how cold can they tolerate?

I'm about to get some single comb brown leghorn chicks from the feed store on Friday. I know this won't be an issues until next winter, but I'm wondering if I will need a heat lamp in the coop? I'd rather not, due to fire hazard, but I don't want any frostbite either. I live on Camano Island, WA. Our average low in January is 34, but it can get down to around 20 occasionally.

I thought I was going to have to wait another year or two to have chickens again, but then this free coop came into our lives (see link below). Obviously it needs a door and a new roof, perches, nesting boxes, etc., all of which it will have very soon. It is insulated. It's about 4'X4'X4.5', so I'm thinking big enough for about eight Leghorn and EE hens, right? Where should I put the ventilation?

https://www.facebook.com/froggullyfarm/posts/552687511567670

It will really depend on your coop. I have leghorns who have done well on nights that have reached 9 degrees. Thankfully, we usually only have brief spells of temps that low then two weeks later we are in the 40's.

The trick is to make sure you have enough space without having too much space so that the chickens can help keep each other warm without getting on each other's nerves and making sure you have adequate, not too much or little, ventilation. This is where the frost bite would come in. Keep the ventilation high up in the coop to whisk away the ammonia from their droppings and prevent any drafts.

As for the lamp, it is best to not put one out if you can get away with it since it is hard on their systems to try to go back and forth with adjusting to the temperature differences from inside and outside.

I hate to sound like a Debbie Downer, but that coop is way too small for eight hens. Four, maybe, and even that may be pushing things. You'll also need to add lots of ventilation. Temperature doesn't cause frostbite, moisture does. Birds can easily tolerate negative temperatures as long as it's dry. Moist cold is what causes frostbite and respiratory issues. There are lots of threads in the coop design section about adding ventilation and how much is necessary.

What if I add an enclosed run? They will be out foraging all day every day.

UrbanEnthusiast said:

What if I add an enclosed run? They will be out foraging all day every day.

Click to expand...

The foraging doesn't negate the need for indoor space. It is needed for when the weather is just too nasty to go out. Whether it is cold and rainy or hot and miserable in the summer. During that time they will be "cooped up" and under foot of one another.

I don't think you can physically fit enough roost space for eight hens in that coop. They have to have enough space to get lift off and jump to and from the roost, that takes horizontal space also. Jockeying for position at night also takes room. Any time they're all in the coop, there will literally only be enough space for each bird to occupy her standing area. You have 16 square feet of floor space, a full grown hen takes up more than a square foot just standing still. Take out space for a feeder and waterer if they're in the coop, nest boxes if they're in the coop. Since you're on an island, I'm thinking you're in Rainy WA vs Dry WA. I'm in Rainy Oregon and while my birds do go out in the rain, they spend a lot more time in their coop then my birds did in Dry Oregon. In the winter, your birds will be in the coop a good 14+ hours a day. Yes, most of that will be sleeping, but they start heading in a good while before they actually roost, so they'll need the space. Again, sorry to sound like a bummer, but it's better to head off problems now than be someone on here posting next year about your chickens cannibalizing each other or refusing to go in the coop and getting picked off by predators, etc.

Okay, my husband has devised a plan to expand the coop with a secure lean-to addition as well as raise the roof (it needs a new roof anyway) by the time they're two months old, which will add roosting space. He's also going to build a modest but adequate run before the short days and rain set in by mid October. We already have a ton of hardware cloth lying around.