re: Need to put a weather door on my dog house

Corrugated cardboard is a surprisingly good insulator., if your dog doesn’t like to chew. I repurposed a dogloo type house for a pair of yard cats, and I completely covered the opening with several thicknesses of cardboard, sealing it tight against the house, then cut a small cat sized porthole at the bottom. Worked like a charm, and the duct tape and cardboard lasted through about 5 winters before it needed replacing.

You can buy pet safe heating pads that are pressure activated, with wire wrapped chew proof cords. Pad heats to something like 60 degrees when animal isn’t on it, then goes higher when the animal lays on it. Will help to heat a too big doghouse if you don’t want to use straw or hay.