Home Alarm Systems

A home alarm system can be part of a complete home protection system, but it is important to view an alarm as just one component of a larger strategy. An alarm system won’t protect your home from a flash flood, a drive-by shooting, or a no-knock BATF raid executed at the wrong address.

Alarm Types

Home alarm systems typically report using one or more of these methods:

  • A loud bell or siren
  • Bright and/or flashing lights
  • A landline or cell phone call to you
  • A landline or cell phone call to an alarm service company
  • A landline or cell phone call to the local police department

Loud noise and bright lights are great to awaken you and to scare the living daylights out of less experienced and less determined bad guys.  If you live in the right neighborhood, they can also attract helpful neighbors.  They are not so useful if you live miles from your nearest neighbor.  They can also be more trouble than they are worth if you live in a neighborhood so bad that your neighbors are more likely to loot your house in the confusion than to help you stop the bad guys.

Alarm systems that use landline telephones to report alarm are not useful against experienced and determined bad guys. Those guys start by cutting your telephone lines.  Systems that use cell phone alarming are more expensive, but are worth the cost if you can afford it.  Unfortunately, even these systems can be defeated with an inexpensive cell phone jammer.

Alarm systems which report directly to the police department are available in some areas.  These eliminate the underpaid and under-trained alarm company telephone operators and they result in faster response times from the police.  They can also result in large fees for false alarms, so you have to make certain that paying these are in your budget if you install one of these systems.In my experience, systems that report to a burglar alarm service company are nearly useless.  The telephone numbers for the service companies are printed on the alarm systems and it is very easy to social engineer the alarm company personnel into turning off the alarm.  In addition, the time lag between the alarm system contacting the company, the alarm company calling the police, and the police arriving on scene, usually means that the bad guys have achieved their goals and left the premises by the time the police show up.

A system that calls you is best — if you are at home or nearby.  If your response time is longer than the police, a notification to you isn’t terribly useful.  Of course, I have been called to respond in-person by out-of-town neighbors whose home alarm system contacted them.  I responded more than 40 minutes before the police, but still missed the bad guys.


Alarm sensors are available in an enormous variety, each with specific strengths and weaknesses.

Common sensor types include:

  • Door / Window Contacts
  • Motion Detectors
  • Glass Break Detectors
  • Photoelectric Beam Detectors
  • Panic Buttons
  • Smoke Detectors
  • Heat Detectors
  • Gas Detectors
  • Water Sensors
  • Humidity Sensors

Door and window contacts are the most common type of alarm sensor.  They are fairly simple and reliable, although they do fail due to age and wear. They are also easily circumvented by simply breaking windows instead of opening them.

Motion detectors are easier to install, but can lead to frequent false alarms due to children and pets inside the house or wild animals and delivery people outdoors.

Glass break detectors are a good backup to door and window contacts, but they have their own limitations. Most glass break detectors operate by detecting the sound of breaking glass, although some work by detecting the vibration from the shock of the glass breaking. Either system can be defeated by using an inexpensive glass cutter.

Photoelectric beam detectors can be more reliable than motion detectors and have fewer false alarms, but they are more difficult and expensive to deploy.

Panic buttons can be very good, particularly the small wireless units.

Smoke detectors are legally required in some areas, however they are well-known for generating false alarms. Heat detectors are more reliable, but by the time a heat detector trips it is often too late to save the property.

Gas detectors, carbon monoxide detectors, water sensors, and humidity sensors make good sense in certain environments. This depends upon the relative threats of each to your home and your family.

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