How to Protect Home for Break-in Using Door & Window Sensors

How to Secure Windows and Doors from Burglars via Wireless Sensors

Secured doors and windows serve as the front line of defense for stopping home break-ins. Whether criminals kick a door in, find the hidden key, or it was simply unlocked, just over one-third of all burglaries start with someone brazenly entering a home through the front door. Another 23% of burglars break in through a first-floor window and 22% creep inside a back door.

Burglar-proofing windows and doors without making your house resemble a fortress can be a challenge, however. Together with reliable locks and sturdy doors, wireless door and window sensors are helping people lock down their home’s perimeter in an economical, unobtrusive way.

Burglars are three times more likely to break into houses without security systems—but only 17% of U.S. homes have them installed, according to a New York Times report. And a new generation of smart wireless security systems that rely exclusively on cellular communication are acting as even better deterrents, providing a solution that’s always transmitting—and can’t be shut down by internet and power outages or criminals with wire cutters.

How Window and Door Sensors Detect Home Break-Ins

Wireless door and window sensors form the backbone of a smart home security system, standing guard at any entry point. In fact, these small but powerful devices are fully compatible with almost anything that opens and closes. This means they can not only safeguard your home from criminals but also protect your loved ones from dangers within your house like gun, liquor, and medicine cabinets. Many are powered by batteries that can last six years or more.

Here’s how wireless door and window sensors work: they generally come in two separate pieces; a sensor installed on the frame and a magnet attached to the door or window itself. They can either be surface-mounted or recessed to make them even less visible, which involves drilling a small hole. It’s essential to position the two pieces right next to each other so they are able to interact.

Inside the sensor is a “reed switch”—the same type of electrical switch that puts your laptop in sleep mode when you close it. This switch is comprised of electrical connectors placed slightly apart. If a magnetic field sits parallel to these connectors, it pulls them together and creates a closed circuit.

Opening a door or window and separating the magnet and sensor breaks the magnetic current, triggering an alarm if the system is armed or typically a chime if it’s not. An alert can also be sent to the owner’s smartphone about unusual activity inside the house. If the home is professionally monitored, the nearest emergency response center will be contacted to dispatch help if the homeowner or any installed cameras don’t indicate a false alarm.

Kicking in a door won’t enable burglars to bypass door sensors. But window sensors can be augmented by wireless glass break sensors, which detect the sound of a window shattering within 20 feet.

Wireless door and window sensors also communicate if something is left open, their battery is low, or there’s a potential tamper event. Each sensor sends a signal to the alarm control panel roughly every hour and a malfunction is logged if one is missed. The control panel then alerts the homeowner and monitoring center about potential problems.

To keep their signal secure, best-in-class door and window sensors come with a unique transmitter identity that’s programmed into their alarm control panel. That way, your door and window sensors won’t be recognized by a neighbor’s wireless security system, and vice versa.

Placing Door and Window Security Sensors: What to Keep in Mind

How you place your door and window sensors will determine how effective they are. Ideally, they are attached to every window and door in your house. But if budget constraints mean choices have to be made, it’s important to prioritize places where burglars are most likely to break in, such as the front door, the back door, and ground-floor windows on the rear and sides of your house that aren’t visible from the street. Protecting children is another priority, sending alerts if a child’s bedroom window opens or a toddler opens his door at night.

Many homeowners also opt to add glass break sensors for greater peace of mind, or substitute them in rooms where the cost of placing window sensors on every window adds up. Though each of these devices is more expensive than a single window sensor, the whole room may sometimes be covered by a single glass break sensor—cutting costs in places with multiple windows and openings.

Of course, using both types of sensors is the best answer for how to prevent break-ins through windows by making it nearly impossible for home invaders to avoid activating your security system. While burglars generally prefer opening windows or doors instead of breaking glass—which is noisier and risks injury—they won’t hesitate if it means not triggering an alarm. And certain large openings, like a sliding glass door in the rear of the home, may be better protected by glass break sensors.

Preventing False Alarms and Interference

Door and window sensors offer a simple, reliable solution to secure the perimeter of your home. More often than not, accidental alarms are triggered by human error such as forgetting to turn off the alarm when you let your dog out in the morning.

But a simple maintenance step can also prevent false alarms. The adhesive that holds sensors in place can lose strength over time, especially if you live in an area with high humidity. While your control panel will alert you if your sensors aren’t functioning properly, it’s a good idea to periodically check that they aren’t slipping out of place, which could trigger accidental alarms. Security companies that monitor systems or the occupants themselves can also virtually troubleshoot wireless sensors for issues.

Interference is rarely a concern with door and window sensors in residential systems that rely on reliable, short-range radio frequencies to communicate with the control panel. External obstacles that might cause interference—such as large amounts of metal, thick concrete, or heavy mesh wire within the signal path—are not commonly found in homes.

Signal disruptions can also be caused by placing wireless sensors in a “loud” area where too many different types of signals are clogging the space. But transmitting over a secure frequency vastly reduces the chances that crowded airwaves will keep the sensor’s signal from reaching its destination.

If a home is very large, a wireless repeater can usually solve the issue. These devices work similarly to WiFi extenders, capturing the signal they hear at the expected frequency and repeating it as a way of doubling its range.

Door and Window Security: Locking It Down

Of course, while door and window sensors serve as an effective first line of defense, pairing them with other simple security measures is the best way to burglar-proof your home.

Keeping doors and windows locked at all times, even if you’re home, is a simple and surprisingly powerful way to reduce your chances of intrusion. Window break-in incidents increase in the summer, when people often forget they opened a window to enjoy a cool breeze. It is also helpful to install deadbolts and remove shrubs near doors and windows, which can offer burglars a place to hide. Window locks that can be seen from the outside also offer extra protection. Since criminals have limited time to do their breaking and entering, anything that looks like a complication becomes a deterrent.

It only takes one security weak point for an intruder to gain entry, and doors and windows pose the greatest risks. Failing to secure them is like rolling out a welcome mat for burglars. And wireless window and door sensors—deployed properly—are an essential part of any smart home security system.