Looks really cute. My three bantams, which are pets do not generate much heat. In the classic there is an air gap above the droppings tray. I sometimes used to test the internal temperature, in the morning before opening the coop door, just by putting my hand through the egg port, and it seemed to be no different from the temperature outside. With the jacket in place I can now detect a little warmth. The classic coop is pretty anyway, but the jacket does make it look even prettier. I have had it for several weeks and the rain has been heavy. I did not expect it to be waterproof, but so far it seems to be. Lots of other things would do the job much more cheaply but would not have looked so good. It depend on your priorities and number of hens.