Minecraft wiki entry for Island_survival, associated text: Once you are in a position to build an actual home base, note that islands often have limited space available. Therefore, you don't have much room to maneuver with if you build your house on the island itself, especially if it is a small island. A better approach is to build your base underground. Alternatively, you can build a platform on the water by placing a block on top of kelp to start the platform, then build your house from that starting point it and connect it to the island with a bridge.