Minecraft wiki entry for Tips_and_tricks, associated text: If the shelter was made out of wood at first, then players may want to change it to something more blast-resistant, like Cobblestone, or even obsidian, if supplies allow. However, resistance isn't always a top priority, and you may just want to build a nice house, if that is the case, then just be wary of any nearby mobs, try to spawn proof the area to the best of your ability, and possibly put a border around your house with a fence.