Being a less attractive target than your neighbours, either by being a bigger hassle or by looking like there's nothing worth stealing.

Provide universal health care, low cost.of living to income ratio, free higher education, strong community building, and walkable cities.

Reinforce your doorframes and window frames, preferably with steel. The dinky pine wood frames of residential doors and windows are hilariously easy to kick in, and the thickest steel door and the meanest window bars in the world won't mean much when an attacker can simply kick them out of the frame with a minimum of effort.

You will probably find that doing this is in fact deemed illegal by at least one entity in your local hierarchy of state/county/municipality. I'll give everyone three guesses as to why.

Lesson from South Africa: by the time they are at your door it's too late. Perimeter fencing, preferably a 2m high wall with razor wire AND electric fence on top (including on gate). Garden: floodlights, motion sensing alarms, beams, AI cameras. All doors and windows: bars and security gates. Inside: separate living and sleeping area with lockable gate in the hall between. Panic buttons..

None of that is going to stop a legal intrusion, each just buys you time before the paid security company arrive with guns to chase away intruders. Given time, any determined attacker will get in eventually..

Who is your enemy?

If it is just some random burglar, create some fear with triple locks and cameras and you are good.

If it is a government operation, you better leave the country before they even start looking for you.

Top 3 tools that will get you most of the way there.

1. Steel door frame reinforcement + steel or solid core wood door. The door jamb is the weakest link here. Cheap steel reinforcement with long screws are an easy win. A quality lock is a good idea.

2. Security window film. Best done when the windows are manufactured, but they will deter most people who were counting on a quick smash and grab.

3. Dog. No one wants to mess with a dog. Lots of dual purpose family friendly breeds who instinctively guard the home from intruders and can smell the adrenaline of people who don't belong.

These three things will get you 80% of the way there for 20% of the cost. Cameras just give you memorabilia of that time you got robbed and rarely help prosecution and even less in recovery of stolen goods.

American home

2nd amendment has entered the chat

Edit: Jesus christ what the fuck? They're going door to door?

We're so cooked

Judging by the link in the OP, the concern is the possibility of ICE or other federal agents breaking in. It's not the same as dealing with a random intruder. About the best you can hope for is to slow them down, maybe giving you time to get away or for legal assistance and the media to arrive.

Given that, I'd concentrate on making the house more sturdy: steel framed doors, steel rolling garage door, properly installed security bars/screens on windows and so forth. And maybe start with a solid masonry house.

Probably not realistic for most people, but then a few years ago I wouldn't have considered the risk realistic either, and here we are.

As a locksmith, I can tell you what I tell my paranoid customers. Buying the greatest lock in the world doesn't do shit if you still have first floor windows.

Layers.

Plant something with thorns or pointy leaves to block easy access to windows. Even better as a hedge around the whole property. Anti break film on windows. Heavy duty exterior doors. Motion sensing lights. Cameras, +1 for cameras with built in lights that can recognize people and automatically turn on.

Every layer should either strengthen, increase risk of being caught, or make access painful. They will go towards easier targets.

If you asking how you secure your residence against ICE…good luck with that. They have legal access to an expansion of the Patriot Act for warrants, and they have toys they’d love to use against any home security. All that physical security is going to do is give them probable cause.

Gravel around your house. Bad guys don't want to be heard.

Exterior lighting everywhere, bad guys don't want to be seen.

Build a moat.

It's not impenetrable, but let's be honest, who's crazy enough to break into the house with a moat?

Have you seen the film Home Alone 2?

The ONLY way to stop someone who really really really wants into your house from entering your house. Is to not have a house.

Having two locks including a proper deadbolt with a decent type of key. You want a deadbolt that goes deep into the door frame, not a cheap one that barely hits the strike plate. That and locking windows with window film will keep most people out.

Nothing will keep someone out who really wants to get in. You just need to make the hassle greater than their desire to get in.

Home Alone has some solid ideas

Alligators.

Oh right. Can you get some pet geese for the outside? Nothing louder than geese

In response to law enforcement, make sure you know your rights. If they are truly just conducting door to door operations, they would have no legal basis to enter your house. That might not stop them from fabricating some exigent circumstances (legally defined term that would come into play). But unless you open the door and/or invite them in, they can't legally come in.

There are two levels to this:

1. Do you want to stop someone on the outside from gaining entry?

2. Or do you mean stopping someone AFTER they have gained entry?

If 1 - The usual steps, cameras, lights, barriers to entry, no trespassing signs, that kind of thing. In our case, an automated light worked wonders. Dude walked up our driveway, took one step on the lawn, lights came on, and he went home to re-think his life choices.

For 2, if they have already gained entry, know your local laws on lethal force, duty to retreat, stand your ground, and castle doctrine. Easy to Google - "your city/state" + any of those terms.

In MY state, lethal force is only allowed in 3 circumstances, one of those three is burglary.

https://oregon.public.law/statutes/ors_161.219

"Committing or attempting to commit a burglary in a dwelling"

Adopt a pair of Doberman Pinscher's that were trained Elite Spec Ops.

Were I in a less secure neighborhood: Deadbolt, second deadbolt, dog.

Better door, better lock, better strike plate, longer and stronger screws. The rest can be visual deterrents like cameras, window sensors, and proximity lights that make them visible to neighbors and drivers.

Surveillance both overt and covert backed up off site and with battery backup. Guard dogs.

Those two will make people pause. But let's say someone says fuckit they're coming in anyway. And you want more than your typical 2A stuff?

There's a lot you can do now with facial recognition and stepper motors. Chemical deterrence. Visual/thermal deterrence. Pretend you're Kevin Mccallister.

Above all that, be tight with your neighbors. Community, community, community.

The goal is to make your house a slightly harder target than some other house. Go for the easy stuff first like keeping the property well lit, lock your windows and doors. Close your blinds so valuables cant be seen from outside. Something people dont often talk about is getting friendly with your neighbors. They can be an extra set of eyes out for anything suspicious.

If you're willing to spend some money, plant thorny bushes under vulnerable windows. Get a security system, or just put a fake security system sign in your yard. Put up cameras.

An easy one is to replace the screws for your door hinges and deadbolt with nice, long, 3 inch screws in place of the tiny ones that are usually used. They longer screws will extend into the wall studs instead of only the doorframe. Makes it harder to kick in. You can also buy metal strips for reinforcing your door jam that aren't too expensive.

One access point I think people tend to overlook are garage doors. I put mine on remote switches so I can completely power them off at night. Even if someone got my garage door opener or one of those spoofers, they wouldn't be able to open the doors.

Just a few ideas off the top of my head.

3" door screws and a good lock.

Also AR15, if you legally/mentally can. Last line of defense, but without it the last line is the door/windows.

If you just want to prevent opporitunistic break ins then you just need to make your house a less appealing target than the neighbors. A sturdy door, motion activated lights, and a dog can do that easily enough. If you want to go the extra mile then put up a few cameras. The cameras don't even need to be real. I used to work for a fortune 500 company that made extensive use of fake cameras on their properties. The trick there was that they also had a few identical looking real cameras as well so unless you had insider knowledge, you would have to consider all of the cameras real.

Now if you want to stop someone who is determined to break into your house specifically then that gets trickier. You will never stop someone determined enough so the goal is to just make the process of breaking in as noisy and difficult as possible. You will want a good and properly mounted deadbolt on all your doors. By properly mounted I mean, throw out those dinky 1" screws that came with the deadbolt plate and mount that plate with some big old 4" long screws. A deadbolt plate just screwed into the doorframe does little good. But if you screw that thing clear through the door frame and into the (preferably doubled up) stud behind it, then bashing in your door goes from requiring a swift kick to requiring a ram or a sledge. Also, if you don't like the look of bars on your windows, you can just apply huricane laminate to your windows instead. It's a film that is designed to be applied to windows in huricane prone areas to prevent debris from flying through the windows. It also makes smashing in your windows a tremendous pain in the ass. The glass will still break but it will all be held in place by the film similar to a broken car windshield. It is possible to get through but it is a very time consuming and conspicuous process. Finally, cameras. Now that you've made it a pain to get through your doors and windows, you want to be sure that anyone who would still be willing to put in the effort also knows that they're being watched the entire time they're breaking in. Yes you can still smash in a door with a proper deadbolt or smash in a laminated window but few people are willing to spend that much time on camera being recorded committing a crime. Beyond those measures your walls become the weak point and there isn't much you can do about that without rebuilding the house.

Not really much, tbh.

Decent quality door locks
Clear line of sight from the street to likely entry points
Loud alarms so if they do break in they're not likely to stay long

If someone wants to get into a house, there isn't much you can do to stop them unless you're rich and can afford exotic shit like bullet proof glass windows and thick metal reinforced doors.
All to can really do is discourage crimes of opportunity by making them seem like bad opportunities.

The critical question is “who?”.

Most break-ins are targets of opportunity. Given that you can’t change to a less risky neighborhood, you could have no outward signs of profitability, no easy/quiet entrance, signs of people around, lights, cameras. And remember, they’re not coming in the front door: they’re looking for an Inconspicuous, weak point. You just need to be less of a target of opportunity than your neighbors.

Someone specifically targetting you will be much harder. Someone with skills will be much harder. At the extreme, no consumer lock is safe against lock picking and no consumer door is safe against police battering ram.

I have a side door with a broken jamb, and speculate that someone kicked it in at some point (before I moved here). One of the first things I did upon moving in, was add long screws to the latch and hinges so it’s anchored in the nearest joist rather than simply the jamb. Supposedly that makes it much more difficult to kick in - someone might give up when it is taking too much time and they are creating noise that could attract attention. I also have a light and a doorbell cam, so they would be visible and on camera doing it. And a dog

At one point I came across an article recommending steel supports behind the jamb, and would really like to do that when I replace the door. It looks like a normal door but the jam is no longer a weak point. Unfortunately no one seems to know what I’m talking about though

Blow it up

Lights, cameras, door armor kit, decent locks, and detergents near windows (bars work, but so does planting a rose bush under the windows. Lastly dogs that bark when one near your doors.

This will.help a lot. Statistically the best impact is a dog or two.

You can go hardest by adding electronic security shutters and a serious storm door over every exterior door..

Very general feedback. I've been slowly doing all of the above for years. Have it all except shutters (no need, windows too high) and storm doors.

But if they get through the door armor, security camera alarms and pitbulls ill have plenty of time to grab my shotgun.

God help them if they hurt my pitbulls.

A big dog or a motion activated speaker that plays big dog noises.

Turrets?

Shotgun. Single best thing you can have.

It depends on whether your adversary is motivated and equipped, your resources, and what visibility you would like to permit. 

Let's suppose you have a poorly equipped adversary, a couple thousand to spend, and you want it to be invisible.

When a door is bashed, the wooden jamb breaks at the lock. So you could go bash resistant device, I believe there are inserts that make bashing significantly harder. Or you can go with a steel door and steel jamb.

For windows, a sheet of polycarbonate glued to the outside should make them resistant to rocks and small arms fire. You should be able to break the glass and kick out the polycarbonate in the event of a house fire.

Check your slider door that it can't be levereged upward and removed while shut.

Landmines. When they crowd around the guy with a leg blown off you ambush them.

Window bars

Can't break in if they can't find your house. Hide it!

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.

Given unlimited time for whoever to break in undisturbed, nothing is secure.

The relevant measure is how quickly someone could break in, without preparation and then with. That's kind of how they rate safes.

If you're not Maduro and the goal is just to get away before they're in, people have mentioned some good options to slow whoever down (alongside the silly suggestions). I'd also add trying to look unprepared, so they don't come prepared for more than a door or window themselves, and having a non-obvious escape route to use in those critical seconds.

Of course, if it's an authority, after you've run away you're down a small-ish house.

Having a house with windows already 4 - 6 feet off the ground, security bushes around the whole house, metal shutters for first floor windows, and as many bars or a brace for the doors.

Shoot everyone who goes near your house

Smoke machines with strobes and a really fucking loud siren. Unable to see, unable to hear.

Owning a gun. Don't shoot to kill, shoot to send a message. If the thief knows you're not fucking around, they won't try that shit again unless they're dumb enough to think you've trashed the gun by not needing it.

And only shoot to defend yourself, target non-vital areas if you're able, shoot for graze shots. But don't shoot to kill if it can be helped.