I use the back half of my garden shed as my chicken coop with the run attached at the side and a coop pop door. I live in Northern Alberta, Canada and this is my first winter with chickens. All my non chicken friends and family are telling me to close up the coop door at night to keep the chickens warm. Winter is upon us up here and it is known to get an average of -20 most of the winter. The run is fully plastic wrapped with a metal roof, I can still go in the run and feed and sit with my chickens with just sweat pants and shirt on and cotton gloves, but I know that will be ending soon. I insulated and vapor barrier with 1/4 plywood walls, the loft above is about 1 1/2 feet to the peak of the roof stuffed solid with hay. I have an indoor/out thermostat which I can read in the house and so far it's only made it down to -2 in the coop I only have a 60 watt light in the coop at this time but plan on getting an heat light next week.