These are some outdoor cat shelters that we put together for a feral colony living near the lakeside.
We used these near the shelter, before we built smaller single units, so they have a worn look. New items may attract attention, which is why we decided to go with these older bins. We had already cut doors in one of the sides, and we lined them with bricks in the bottoms, to stop them from moving with strong winds.

1. We used 2cm thick foam insulation and thin plastic insulation, that we cut to size. We cut the foam to the size of the bottom, and layered that on top of the bricks.
2. We then cut four walls of foam insulation, to fit inside the bin, and taped them together.
3. We cut clear plastic insulation sheeting to line the foam, taping them together, so that the cats won't scratch the foam.
4. We cut a piece of foam to fit the top, and attached it with tape on one side, forming a hinge, so that it can be opened to check cats inside.
5. We cut holes in the foam at the open holes in the bins.
6. We put blankets inside for added warmth.
7. We locked the bins closed, so that they won't blow open in the wind.
8. We placed them in a level, somewhat sheltered location.
9. We used permanent marker to write our name and phone number on the boxes, hoping that someone will call us, if there is a problem.
10. We released Nigel not far from the new shelters, but in a safe place, so that he could run away and return when he feels more comfortable.