Whether you're expecting a quote for an intruder alarm system or want to check how an older installation of yours was done — here's what the process should cover, step by step.
An intruder alarm system is only as good as its installation — the most expensive control panel on the market won't help if a sensor is positioned wrong or the cables aren't secured. Here's what we include in every installation, and what's worth checking if you're expecting a quote from another company or want to review an old installation.
With intruder alarm systems, the difference between "it works" and "it works when it has to" is almost never in the device itself. The typical problems we run into when inspecting other people's installations are simple: a sensor aimed at a radiator that triggers a false alarm every evening; a magnetic contact fitted with a larger gap than allowed on the moving part of a window; a siren mounted so low it can be pulled off by hand; a battery nobody has checked in years.
That's why a good installation starts long before the first hole is drilled — with the question of what exactly needs to be protected, and from what. The same system installed in a warehouse that's empty at night and in a family home with children and a dog has to be set up in a completely different way. The checklist below follows the order in which the work is done in practice: before, during and after the installation.
At its core, the system is a control panel (the "brain") with sensors, sounders and control devices connected to it. The panel monitors the state of every zone — a single point or a group of sensors — and when the system is armed, it responds to a violation: it sounds the siren, sends a notification to the owner's phone and/or sends a signal to a monitoring center.
Motion sensors (PIR) respond to a change in infrared radiation — that is, to a moving heat source within their coverage area. Magnetic contacts detect the opening of a door or window, and glass break detectors pick up the characteristic sound or vibration of breaking glass. Each type has its strengths and weaknesses, which is why a system rarely relies on just one.
| Component | What it does | Typical installation mistake |
|---|---|---|
| Control panel | Processes signals from the zones, controls the sirens and communication | Placed where an intruder can easily reach it, or far from the power supply |
| PIR motion sensor | Detects a moving heat source in its range | Aimed at a window, radiator or air conditioner |
| Magnetic contact | Signals when a door or window is opened | Too large a gap between the magnet and the contact |
| Glass break detector | Responds to the sound or impact of breaking glass | Installed in a room the sound of the glass doesn't reach |
| Siren | Sounds the alarm on site and deters the intruder | Mounted at an easily reachable height with no protection against removal |
| Keypad / app | Arming, disarming, checking the status | Codes shared among many people and not revoked when an employee leaves |
There is no universally "right" intruder alarm system. The table shows how the selection logic changes with the type of site — these are guidelines, not ready-made recipes; the specific solution always depends on the survey.
| Site | What to focus on | What to watch out for |
|---|---|---|
| Apartment in a block | Magnetic contact on the front door, PIR in the hallway; on a ground or top floor — also on the windows/terrace | Pets and false alarms; siren noise reaching the neighbors |
| House with a yard | The perimeter of ground-floor entrances and windows, an outdoor siren, outdoor sensors if needed | Outdoor sensors are sensitive to wind, branches and animals — careful tuning is needed |
| Shop or office | Contacts on the entrances, PIR in the sales floor, monitoring to a monitoring center | Different users with different rights; defining who arms and disarms |
| Warehouse or production site | Zoning by room, a reliable link over two independent paths, a link to video surveillance if needed | Dust, humidity, temperature extremes and large spaces that affect the sensors and the wireless range |
At handover it's useful to also receive a written list of the installed zones (which sensor is where and how it's labeled in the panel), the access codes, the support contacts and the warranty terms. Without this information, in a year or two nobody will remember which sensor corresponds to which room.
An intruder alarm system is not "install and forget". Wireless sensors run on batteries that wear out; the panel usually shows this, but only if someone is looking. The rechargeable battery in the panel also ages and holds less over time — it is replaced according to the manufacturer's recommendations, not when it fails.
A sensible practice is to test the whole system periodically: walking through the zones, checking the siren, checking the link to the app or monitoring center. A test is especially important after renovations, rearranging rooms, replacing windows or doors, or getting a new pet — all of which change the conditions the system was set up for. Also check that notifications keep working when you change internet provider or router.
It depends on the site. A wired installation is better suited to new construction or major renovation, when the cables can be hidden, and it doesn't depend on batteries in the sensors. A wireless one is convenient in lived-in homes where you don't want to chase walls. A well-executed wireless system is perfectly viable, as long as the signal at every point has been checked.
There's no universal number — it's determined by the survey: the entry points, the route an intruder would take, and where the valuables are. It's better to have fewer sensors in the right places than many placed without logic.
Don't switch the system off and don't let the sensor "get used to it". False alarms almost always have a cause: a heat source, a pet, a weak battery, a weakened wireless signal or a loose magnetic contact. Call the installer — the sensor is usually moved or tuned more precisely.
The panel keeps running on its backup battery, but only for a limited time. If the link to the app or monitoring center depends on the internet, it's good to have a backup communication channel, for example a mobile network. Clarify this at the survey stage.
Not always, but it's the only option that provides an on-site response when the owner can't respond alone. If you insure the site, check the insurer's requirements; the regulations in force may also set conditions depending on the type of site.
If you need a consultation, the Select IT team carries out a survey and prepares a quote for your specific site.
We'll carry out a free site survey and propose a configuration matched to the real risk level of your site.
