Ive had some trouble building floors inside buildings, specifically storage buildings like the one in the added pictures, once you start building a larger floor in the second floor, that area will start to appear as "outside" even though it has a ceiling above it and rain pours through cosmetically. Temperatures in that area does not correlate either to the temperatures that should be inside. The difference is inside temperature vs outside temperature, so if you have 22 C in that other area just a few tiles away it drops way bellow ( 10c for example ).