Perhaps heating a house could be possible by having the game calculate an area around a heat source. From there give each block in that area a hypo/hyperthermal value, of course since would be in three dimensions the game would calculate a volume. Preventing the heat from going through building could be done by having the game determine if an object (block, plank, beam) is within heated dimensions. Then based upon material of the obstruction a value could be subtracted from the thermal value.
Given everything else going on with the game at the moment, this would be a pain to implement where it wouldn't cause lag.
i do like the idea of an enclosed space being encouraged/rewarded in terms of heat retention. like a campfire out in the open air shouldn't be as good at warming the player/surrounding space as one in a cave or building, imo. that sort of limitation makes it feel more rewarding to build a proper shelter, and gives the game a nice cozy vibe, too.