Today's alarm systems are really effective, easy to fit and easily adapted to suit your home. Intercoms and CCTV cameras give you other ways to prevent unwanted intruders.
There is plenty of choice when it comes to alarm systems. Whilst most include a central control for your home, you can select a combination of different sensors to be used around the house. If triggered, these sensors will set off the alarm.
Infrared movement detectors (called PIRs) can be fitted high up in the corner of each room. These trigger the main alarm if they sense a door opening or an intruder walking across the room.
You can also fit magnetic contact detectors on your doors or windows, which set off the alarm if the magnetic plates are disturbed.
Most alarm systems use a combination of these elements - bringing them together with an interior control panel and an exterior casing that contains the bell or siren.
Some alarm systems let you isolate different zones in your house. For example, at night you may wish turn on the alarm downstairs, but leave it off upstairs so you don't trigger it on a trip to the bathroom. If you have pets in your home, consider leaving one room without any movement detectors so they have somewhere to stay without setting off the alarm.
It's much easier to install wire-free alarms than wired versions - but you'll need to change the batteries from time to time. You can add as many PIR sensors or magnetic contact detectors as you like.
There are limits to the number of accessories you can add to a wired system. The components need to be linked, and the control panel needs an electricity supply. However, on the plus side, some wired alarm systems can be monitored by a security company, who'll alert the police if it goes off.
No burglar wants to be captured on camera, so CCTV is a very effective deterrent. When the PIR sensors positioned around the edge of your home detect an intruder, the CCTV cameras start recording.
Look for helpful features such as night vision mode, the ability to record images captured by the system and anti-fogging cameras to get the best picture quality. Some systems will even allow you to remotely access your CCTV from a smartphone, enabling you to check on your home whilst away.
Built-in speakers and microphones let you check who's at the gate or front door before you let them in. Some intercom systems feature video cameras and screens, so you can see your caller as well as hear them.
Wireless systems are easiest to fit, and offer similar functions to wired systems.