The walls I built can't recognize in ISOREGION.
At first it wasn't like that, but then when I updated to 41.72 unstable my character began to feel the coldness and when I looked at the temperature it's the same when you are outside the house.
I thought it was broken since it was unstable but when I tried to create a new game and tested building it worked, the walls are recognized in ISOREGION.
Sorry for my bad english.