Just make sure no gap is bigger than 1/2" to keep predators out. As others have said you need good draft free ventilation in the winter to allow the moisture out so they don't get frostbite in their combs. Remember a chicken comes with a down filled variable thickness blanket built in and a...
Dogs are your #1 threat, if a dog gets inside your run it will kill every chicken... I know. Best plan on a dog proof run, 5' chain link will keep them out.
JT