Why would Vader's chamber be so isolated like it was specifically built into the ship? Vader was not the leader of the Empire. He wasn't even necessarily respected by his inferiors. They feared him, but as we saw in ANH, some even mocked him and his beliefs. Only after the prequels do we now consider Vader the most important person in the entire galaxy, but that is not how it originally was meant to be. I think it makes more sense for his meditation chamber to be just a room where they put his life-support pod, close-at-hand because he needed it. But they didn't build the entire Executor around it.