This article explains some of the design constraints which apply when using outdoor lighting for security reasons. A careful and well thought out design is needed, because in some cases badly designed security lighting can be counter-productive.

 

Security lighting is mainly employed as a preventative measure, deterring physical intrusions onto a residence or other type of property. Of course, as well as deterring intruders it will help detect and identify any person who still enters the property, and it often gives a feeling of safety to the individual homeowner, or to all the residents in an area which has public security lighting.

 

Nevertheless in some cases security lighting has been shown to be ineffective, or worse, to actually increase crime. The designer should be aware of this possibility, and take steps to guard against it. One way in which the lighting increases crime, is by making the criminal aware of the presence of a possible target. One school in Texas found that vandalism was reduced 55% by turning off lights at night!

 

The security outdoor lighting itself can also be a target for vandals. Lights should therefore be mounted very high, or protected by vandal proof wire mesh or polycarbonate screens. Alternate schemes may include recessing the light itself, while directing the light via a polished aluminum or stainless steel mirror.

 

It is also necessary to protect the electricity supply from tampering and other interference. The electric meter box should be either locked or completely inaccessible, and all control and power lines should be either buried in conduits, or at a height of at least 24 feet. Very secure systems may also wish for further protection, for example by having a standby generator installed.

 

Criminals are also often aware that the outdoor lighting can actually create glare, and therefore hide the criminals activities. Generally bright and unshielded floodlights can cause this problem, and should often be avoided.