We've had chickens the last ~10 years, and have never had much trouble with cold, even occasional dips below 0F. We routinely get a week of single-digit nights, and while I'm sure they don't love it, there have been no lasting ill-effects.
Heating a coop is a very bad idea. Lots of coop fires, and the chickens don't need it in most "lower 48" climates. All you're doing is making them soft, and ensuring a dependency on heat, which they otherwise shouldn't need. They are wearing down coats, you know!
Careful about closing the coop up, as you had mentioned in the OP. Chickens (and their poop) put off a huge amount of moisture and ammonia into the air. As much as you want to protect them from the cold, they need constant ventilation. Just make sure it's not drafting directly onto them. A typical method is a vent down low and a vent in the roof, covered by a hard awning. I think the rule of thumb is 1 sq.ft. per chicken in smaller coops, but this can be reduced in larger coops. The forum at backyardchickens will clear you up on that.
My own coop is 16 sq.ft. and standing height, with a sliding window and a 4 sq.ft. vent in the roof. The vented portion of the roof is covered by the roof of the adjoining run, so no rain or snow gets in. I keep the sliding window open wide in summer, and just cracked about 3 inches (so maybe 48 sq.in. opening) in winter, with the opening being the farthest corner of the coop from their roosting bar.
Buying breeds that are known to be suited to your climate is key. I tried Brahmas at one point, which love the cold, but died of heat stroke in our summer heat waves. I've had good luck here near Philly with Barred Rock and Asian Black, as well as an Easter Egger that is just an incredible laying machine the last 6 years. That Easter Egger lays a beautiful green egg every day for about 9 months of the year, but unfortunately since all Easter Eggers are mutts of one sort or another, I doubt I'll ever be so lucky to get the same again.
Heating a coop is a very bad idea. Lots of coop fires, and the chickens don't need it in most "lower 48" climates. All you're doing is making them soft, and ensuring a dependency on heat, which they otherwise shouldn't need. They are wearing down coats, you know!
Careful about closing the coop up, as you had mentioned in the OP. Chickens (and their poop) put off a huge amount of moisture and ammonia into the air. As much as you want to protect them from the cold, they need constant ventilation. Just make sure it's not drafting directly onto them. A typical method is a vent down low and a vent in the roof, covered by a hard awning. I think the rule of thumb is 1 sq.ft. per chicken in smaller coops, but this can be reduced in larger coops. The forum at backyardchickens will clear you up on that.
My own coop is 16 sq.ft. and standing height, with a sliding window and a 4 sq.ft. vent in the roof. The vented portion of the roof is covered by the roof of the adjoining run, so no rain or snow gets in. I keep the sliding window open wide in summer, and just cracked about 3 inches (so maybe 48 sq.in. opening) in winter, with the opening being the farthest corner of the coop from their roosting bar.
Buying breeds that are known to be suited to your climate is key. I tried Brahmas at one point, which love the cold, but died of heat stroke in our summer heat waves. I've had good luck here near Philly with Barred Rock and Asian Black, as well as an Easter Egger that is just an incredible laying machine the last 6 years. That Easter Egger lays a beautiful green egg every day for about 9 months of the year, but unfortunately since all Easter Eggers are mutts of one sort or another, I doubt I'll ever be so lucky to get the same again.
