Carpet on the roosts, I don't even want to think about cleaning that mess after a couple of weeks. What good does insulation do in the winter, if the coop is properly ventilated? And by ventilation, I'm not talking about a couple of 2X6" floor grates. The chickens have perfectly good insulation of their own. It's really funny to me, that people put their own limitation of handling cold weather, on their chickens. When in reality land, the chickens are well suited (Literally) for the cold.
How many tales of woe will we read about this year, about burned down coops, and all the chickens in it, due to a stupid and unnecessary heatlamp. Or about some poor frosted up birds, due to being kept in a near airtight box in some misguided attempt to "Keep them warm". Bottom line, they don't need any added heat from us, And they don't want some well insulated, poorly ventilated box to live in.
Jack