Survey your home and determine how many windows and doors you want to be 'switched,' or integrated into the home security system.
Determine possible locations for the control panel and keypads. You might find it convenient to place a keypad close to the front door. You might also want a keypad close to the bedrooms. The control panel commands the system, and the keypads allow you to program the system and turn it, or its components, on and off.
Determine how far away windows and doors are from the control panel so that you know how far wires will be routed if you choose a wired alarm system or how far a wireless system needs to communicate with sensors. Keep in mind that it is difficult to install a hard-wired security system unless your house is still under construction.
Decide whether you want a monitored security system that will be monitored 24 hours a day. The central monitoring station 'watches' your home for a monthly fee. A less expensive alternative is a basic sensor system with a dialer accessory that connects the system to your phone lines and dials preselected numbers if the house's security is breached.
Consider your lifestyle. Does anyone in the family often get up in the middle of the night for a snack? Do you have a large pet that roams the house at night? Such circumstances will influence the type of motion sensor you select and how it is installed. It may also call for you or members of your family to take trips to the keypad to prevent false alarms.