Home security is an industry, and industries sell products rather than habits. This page is an honest account of what each of the popular products actually does, because several of them are worth having and none of them do what the packaging implies.
The short version is that the free measures on the layers before hardware outrank all of it, and the most effective purchase is usually a light.
The honest ranking
Notice that the two strongest are not products.
Dogs
A dog that barks is among the most effective deterrents there is, and it is worth being clear about why: it announces that somebody is in, it announces it immediately, and it does so from inside where nobody can disable it.
Size and breed are largely irrelevant. A small noisy terrier does the deterrent job as well as anything larger, because the deterrent is the noise and the attention, not the animal.
But a dog is a ten to fifteen year commitment, with daily walks, veterinary costs, food, and the problem of what happens to it when you go anywhere. Do not get a dog for security. Get a dog if you want a dog, and accept the security benefit as a side effect. A dog acquired as equipment is a welfare problem waiting to happen, and it is a serious one in exactly the long-emergency scenario this app describes, when feeding it becomes a real question.
A dog is also a genuine asset in the other emergencies this app covers: it hears things, it wakes you, and it is company. Those are better reasons than security.
Alarms
A visible alarm box is a moderate deterrent, and it works as an occupancy and protection cue at a distance rather than because of what it does when triggered.
The audible alarm itself does less than people expect. Bystander response to a ringing house alarm is poor, because false alarms have trained everybody to ignore them. If it goes off while you are out, in most cases nothing happens.
- A monitored alarm is a genuine step up, because somebody responds, and it costs a monthly fee.
- An alarm that texts you is a middle option and is only as good as your ability to do anything about it.
- Fit sensors where entry actually happens: the back and side doors, the ground floor rear, the hall as a catch-all.
- Keep it maintained and use it. An alarm that is never set because it is a nuisance is an ornament, and a dead battery beeping for six months tells everybody the alarm does not work.
A dummy alarm box is better than nothing and is transparently a dummy to anybody who looks, since real ones are recognisable brands with flashing indicators.
Cameras and video doorbells
Be clear about what these are for. They are mainly detection and evidence, and only weakly deterrence.
What they do well:
- Tell you somebody is at the door without opening it, which is genuinely useful for anybody vulnerable or living alone.
- Record what happened, which helps the police and helps an insurance claim.
- Let you see a delivery, a visitor, or a neighbour's check.
What they do less well:
- Deter. People intent on something wear hoods and look down, and the footage of a hooded figure identifies nobody.
- Work without power and internet. Almost all of them stop the moment either goes, which is precisely the scenario this app is written for. See getting a message out.
- Produce usable images at night or at distance. Wide angle plus low light plus movement is how you get a grey smear.
If you fit them, put one at the actual entry points rather than only at the front door, mount them out of easy reach, and make sure something records locally as well as to the cloud.
The law on your own cameras
The part that catches people out, and it is worth getting right.
If your camera captures images beyond your own boundary, including a pavement, a road, a shared drive or a neighbour's property, you are handling other people's personal data, and data protection law applies to you.
In practice that means:
- Put up a sign saying recording is taking place and how to contact you.
- Point cameras at your own property and use privacy masking to exclude what is not yours. This is the single best step and it removes most of the difficulty.
- Only keep footage as long as you need it, and then delete it.
- Respond to requests. Somebody caught on your camera can ask for a copy of footage of themselves, and you have to deal with that request.
- Think about audio, which is more intrusive than video and harder to justify. Most doorbells record it and most people never consider it.
The Information Commissioner's Office publishes guidance for domestic CCTV, and it is short and readable. It is worth ten minutes before you mount anything.
This is also a neighbour relations issue, and neighbours are your strongest security asset. A camera pointing at somebody's front door is a good way to lose the thing that was protecting you. Tell them what you are fitting and where it points.
Signs and stickers
Modest value, and not nothing.
- An alarm sticker or a camera sign contributes to the general impression that a property is protected, which is what the assessment from the pavement is made on.
- They do not work alone. A sticker on a house with a dark side passage and an unlocked shed is not persuasive.
- Avoid signs that overstate. "Beware of the Dog" has the liability problem above; anything threatening reads badly and can itself be an offence depending on wording.
- A neighbourhood watch sign is worth having where the scheme is real, because it implies neighbours who look.
What does not work
- Fake cameras. Recognisable at a glance, no evidential value, and they tell anybody who spots one that the household spends money on appearance rather than substance.
- A single sticker with nothing behind it.
- A key hidden outside. There are perhaps six hiding places and everybody knows all six.
- Leaving a hall light on permanently, which reads as absence rather than presence.
- The radio left on continuously, for the same reason. On a timer, varying, is different.
- A big dog that is friendly and silent. The bark is the deterrent.
- Anything that relies on you being there to use it. Most trouble happens when nobody is home.
- Booby traps or anything set to injure a trespasser, which are criminal offences regardless of who is hurt. See the law on defending yourself.
Spending in the right order
If you are going to spend money, this is the order that gets the most per pound.
- Cut back the hedge and fix the sight lines. Free, and the biggest single change at most houses.
- Lighting at the side and rear. Modest cost.
- Long screws in the door frames. A few pounds, and it addresses the way doors actually fail. See reinforcing a door and its frame.
- Window locks, and keys on hooks beside them. See ground floor windows and glazing.
- A shed lock and somewhere to chain the ladder.
- Gravel on the path.
- An alarm, if you will actually set it.
- Cameras, understanding they are evidence rather than prevention.
- Laminated glass in the pane beside the front door.
And running through all of it, the thing that is not on the list because it is not bought: knowing your neighbours. See community and mutual aid.