Minecraft wiki entry for Before_Village_%26_Pillage, 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 cannot be called "houses." However, if additional blocks are placed behind these, they will be 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":