A useful addition to perimeter security can be exterior lighting, either switched manually or automatically operated. Lighting does have its limitations – burglaries often take place during daylight hours; if the light is activated, someone has to notice it – and take action. Lighting should be seen as an aid, but on its own it is not sufficient to deter a burglar.

The most common form of lighting is passive infra-red which is activated when someone comes into its field of vision. The light can be set to stay on for a set time and then it will re-set if the cause of its activation is no longer present. A passive infra-red unit can activate single or multiple lights.

Lights can be useful on the approach to a front or rear door or garage, not only lighting up if someone approaches your house, but also when you approach, so that you can see if anyone is lurking in the shadows. It must be remembered though that lights can be activated by certain animals. Also, you do not want the light to be activated every time your neighbours go into their garden or when someone walks past the front of your property. However, the field of activation can be adjusted. You must also make sure that your light does not intrude into your neighbours windows or those of passing vehicles – light pollution can often be at the centre of many disputes.