Here’s the issue: your question is mechanical in nature and relatively vague. If the goal is to prevent someone from entering a home, there are many measures one could take. However, I do not believe that is what you mean. What you are actually asking is what to do once someone has already broken into your home. Unfortunately, the answer to that is simple: a 12-gauge shotgun. I understand that many people on this platform dislike firearms. I do not particularly like them either. However, if we are discussing this purely from a mechanical and practical standpoint, the most effective option for home defense is a 12-gauge shotgun. I mean that literally. It is the most reliable means of immediately stopping an intrusion from progressing further into the home. Everything else, moats, gates, high-powered security systems, armed guards, or a medieval motte-and-bailey setup, is either wildly impractical or financially inaccessible to most people. At that point, the question is no longer “How do you physically prevent entry?” It becomes “How do you stop an intruder once entry has already occurred?” That question has already been answered. A 12-gauge shotgun.