It's the way that detects the intrusion the quickest and most accurately. And, that is done how?
Keep these in mind:
• What are you protecting and where is it? [the asset]
• What are you protecting it from and how will it get there? [the threat]
• What accommodations are needed to function with and within the protected area? [your activities]
The goal of the alarm system is to deter a criminal with a siren once an intrusion is detected and to summon a law enforcement (or private security) response. It is also going to provide some insight into the intruders path and possibly their intentions during the attack.
The asset is inside your home or business. There is most likely more than one asset and they are not necessarily grouped together. This makes for multiple areas to specifically protect.
The threat is coming from outside. This may not be true in reality; however it is an assumption for this exercise. It will need to pass through a door, window, wall, floor or ceiling to gain access.
You, your family, or your business associates might want to conduct some limited activity inside sometimes when the alarm is armed. Most of the time the location will be vacated when it is alarmed.
1. All exterior doors should certainly have a magnetic contact or other point sensor installed.
2. Exterior windows should also have magnetic contact or point sensor installed.
3. The areas directly inside the exterior doors and windows should have at least one volumetric sensor.
4. Large areas of glass, or glass that may be targeted by street punks, should have a glass break sensor.
5. Some individual assets may warrant specific protection such as sensors inside safes, or liquor cabinets (for teenagers).
6. The alarm control panel should be in a well protected location (rapid access to this will disrupt the alarm communication and response)
6a. If the communications module for the panel are located away from the panel it too should be well protected.
The Next Step (for the Unoccupied State):
The most likely path(s) that an intruder might use should be monitored by sensors. This offers insight to their activity during the intrusion. The degree of insight comes from the nature of the sensors that are focused on that asset.
The Next Step (for the Occupied State):
Think about where you wish to move while the alarm is armed. Plot this area on a set of floor plans if necessary. Now is it still possible to effectively detect an intrusion with these areas not monitored? In a perfect environment you and your family will be able to use the restroom and walk to each other without activating the alarm. This may not be ultimately possible; although it is with some creative planning. Keep in mind that some burglars have been known to move around the bedrooms of their victims while they were sleeping in the room.
With the sensors planned - we'll jump beyond the whole installation part - there is at least one more step. And it is quite possibly the most important one....