I have buff & lavendar orps, faverolles, dominiques and white rocks, I don't ever use a heat lamp. They live in a 80 year old barn that is pretty drafty and they do just fine. I do feed layer ration free choice and then corn, oats, & BOSS for scratch treat usually daily. 30 hens, usually get 12 - 18 eggs daily. As cold as it has been I am really OK with that. I do have lights that come on at 4am. I am in northern IA, it has been down to 10 below a few nights already, forcast is for about 30 below next weekend. They will really have to roost close together!
I do have a salmon faverolle rooster that had a large beautiful comb, that has now gotten all the tips of it turning yellow/brown, that is heart breaking cause it was so big and pretty going into this winter, but again I do not use any heat source, to scarry in that old barn.

