Picture a house on stilts. Nothing on the bottom two floors except a ton of pillars. The pillars don't allow anything else to be built there, like stairs.
So, basically you jump up onto a couple objects leading to a final jump that allows you to put all your stuff in a chest. Then, you suicide. After that you respawn in your house, open a door by said chest, and grab your stuff. Basically, only you can spawn in your house, nobody can build into it, thus making it unraidable.