Oh Please Help me every time I Leave my Residence My house Starts on fire Why I have no Fire or Lava So Why Does this Happen??
Someone might be playing a trick on you, or it might be jumping from another res (I think this is possible). To prevent this do /res set firespread f. You'll lose the ability for grass to spread though. If you think someone might be doing it use the command /res default too.
Things i would do. First, check your permissions using /res info to make sure no one has access. Type /res set firespread false on your res, this will stop fires from spreading (and also grass from growing).
Or there is another idea, don't build out of wood, or if you do, build out of double wooden slabs, which I believe dont burn and rival obsidian for durability...