Minecraft wiki entry for Blueprints, associated text: Entry stairs are optional for all buildings, and do not spawn if the door/entrance is at street level. A building is spawned above street level has stairs leading straight out from its entrance down to the street level, with cobblestone blocks as a foundation extending below the first floor if the building did not spawn on a flat spot. Also, all asymmetrical buildings can spawn as shown below or as a horizontal mirror image.