Minecraft wiki entry for Legacy_village_mechanics, associated text: Since these doors both have the same number of covered spaces on either side, they don't have an "inside" or an "outside," and therefore can't be called "houses." However If you put additional blocks behind these (or just move them back by one space) then they are 6 blocks away from the far door, too far to be counted, but are still within range of the nearer door, creating the imbalance necessary to call them "houses":