With the weather changing my thoughts often stray to the strays.. cats that is.
Out at my mother in laws people often dump unwanted felines assuming she will care for them. She feeds them, but doesn't want any inside pets, so the kitties are left to the elements. They do have a few shelters but no heating. Since it gets as low as -35°C and sometimes even worse here in the winter I felt they needed something else to keep warm.
So last year 
It wasn't too much work and was quite inexpensive. Best if all the cats seemed to enjoy them!
Supplies we used to make three houses were: 6 plastic containers, three large and three small. The small need to be able to fit a cat or two comfortably
Insulation: we used old pink insulation, styrofoam and hay because that's what we had but there are other options as well.
Something that works really well is Mylar, the stuff they use to make emergency blankets. I was hoping to find some at the dollar store but no such luck so we just used hay instead. If you can find it though you can line the inside with it and it will be very effective in sending the cats body heat back to them instead of absorbing it like blankets.
Then we just used duct tape to seal it all up and a knife to cut out a small door in both containers. You want your door to be just big enough for the cat to fit through but not too big or you'll lose too much heat.
We enjoyed making these and the cats sure appreciated them! If you have stray cats or a feral colony near you, maybe consider making a few to get them through the winter a little warmer :)
❄️💙❄️