@casablanca Thank you :) This time I only buildt boxes for the garage. Some of the strays like to spend the night there (and much time of the day). The garage is part of our cellar, so it's frost-protected. The cats can come in through a cat flap. But two of them don't understand how to use it, so I tied up the flap. Therefore it's a little drafty (and a little colder). I'm happy that the cats accepted the warm boxes with styropor and cardboard immediately. Have a nice day!
