I have a Little Tikes Coop. I started out trying to put hardware cloth on the windows and stuff spray foam in the hollow area of the walls. Decided it just wasnt worth it. My coop is inside a Ft Knox-secured run, so I don't worry too much about predators.
Here's what I did do.
1. Put brick down for a "floor" to keep it from getting muddy in the rain.
2. Spray foam around the joints of the house and up under the eaves on the sides, but not the front and back eaves which were left open for ventilation.
3. Put silicone caulking across the top joint of the roof for weather-proofing.
4. Screwed a long board from side window to side window for the roost. It even sticks out of the window about a foot - the girls love to take turns sitting there during the day.
5. Put an old wooden box in for the nesting box. (they all share the one box and it just sits on the floor - not screwed in anywhere)
6. Found some spray paint meant for plastic the same color as the house to cover up the spray foam - this keeps them from pecking at it.
7. Put a piece of plywood at the back window that has no shutters.
8. For winter I screwed a piece of plexi over the front door windows and used duct tape to tape the shutters closed and keep out drafts.
I have Welsummers and Easter Eggers (cold hearty birds) and the six of them did just fine over the winter - even with three feet of snow on the ground. I did move them to the garage two nights when it went below 0, but I probably needn't have done so. For warmer months, I just keep the shutters open 24/7 unless it is raining, then I close them partially depending on the angle of the rain. Again...I feel I have a VERY secure run that this coop sits inside of.
