The Crime Prevention Website


The limitations

Whilst external lights can be very useful around the house and garden for crime prevention some people make rather exaggerated or misleading claims as to their all round effectiveness.   Here are just a few quotes picked off some retailing ‘security advice’ websites.

“Lights are always a good deterrent”

“Without doubt security lighting is a major deterrent against burglary” 

“Solar security lights are perfect for keeping your residence safe, by discouraging potential intruders”

“This Security Floodlight is ideal for an initial security measure around your home”

I have no doubt that some burglars and thieves have been put off by lights and I’ll explain why in a moment, but having visited many scenes of burglary I can tell you that lights certainly don’t work all the time.  Also consider the fact that a majority of crime takes place during daylight hours.  We seem to be gripped by the cave dwellers notion that lighting fires will keep the wild animals away.  Well they might have done, but the thief is a different beast!

Evidence does suggest that people feel safer at night in well lit public places when they can see everything around them and it is probably true that the same can be said about your home if you can look out onto your lit back garden from the safety of an upstairs window or the patio doors.   It’s just good to be able to check what’s going on in the garden and outside the front door late at night.

Another way that external lighting may help us is if the presence of the light convinces the criminal that what he is about to do will be seen by you or your neighbours or maybe a CCTV camera.  It seems to me then that it is a combination of light AND an increased chance of the criminal being seen that  must work together in order for anybody to claim that light is a deterrent to crime. 

A research paper written in 2004 by Ian Hearnden and Christine Magill and published by the Home Office entitled  Decision –making by house burglars: offenders perspectives  (Available in Library under Burglary) is interesting in that lighting is not mentioned by burglars as something that puts them off targeting a particular house.  To be fair to those of you who think light works all the time the authors didn’t ask the burglars a direct question about lighting.  Nevertheless when they were asked what things were more likely to put them off the main deterrents were:  Evidence of occupancy, the presence of an alarm or CCTV camera and the apparent strength of the doors and windows.  Interestingly, one of these findings does indicate an effective use for lighting, which is to use it to give the impression that you are home.  (See  LightingInternal lighting for the home )

So, you can put external lights anywhere you think might be useful, but which ones should you leave on for some extra security?  You should ask yourself a really important question before you make your decision:

“If I put a light on that wall or above that door and leave it on or have it switch on automatically will an intruder be seen?”

Another related question you could ask yourself is:

“If the light is on or comes on due to the presence of an intruder, who will benefit from the light?”

Think about this scenario:  It’s 2 o’clock in the morning, the outside light is on and the burglar is thinking about forcing a rear door or window below the light.  The burglar cannot be seen by any neighbours or passersby or maybe you live in the middle of the countryside and you’re in bed asleep, or perhaps you’re away on holiday.  Who benefits?

So my advice to you is NOT to light up places that cannot be seen by you or your neighbours.  This is NOT the same as saying “don’t put a light there”.  You’ll probably need the light for all sorts of practical reasons and in this scenario it would be of great benefit for you to be able to switch the lights on from inside the home; putting yourself in control.

Now it’s quite clear that lots of people have thought about these questions already, but have reached rather different conclusions.  This is evidenced by the installation of hundreds of thousands of tungsten halogen floodlights that are switched on by passive infrared detectors with the idea that a sudden bright light shining down the garden will scare away the intruder.  The pros and cons of these types of lights are discussed in detail later, but I have yet to find any evidence that supports their ‘scare away’ effect. 

I perfectly understand why people buy these lights, especially if they’ve just been burgled as it is quite natural for victims to try anything that might prevent themselves from being victimised again.  But you must still ask the questions.  If the burglar has already established that you are not at home (having rung your doorbell or seen you go out) and your neighbours are curled up in front of the TV with the curtains drawn, is the sudden onset of a bright light going to scare the intruder away?  If the sudden appearance of light is noticed will it be reported to the police and, in the absence of any other evidence, will the police respond to a light coming on?   

You may be thinking that I have been rather negative about lighting, but that is not the case.  It’s just that some security measures have their limitations and you will be better off spending money on something that has been proven to work rather than wasting it on something that will have limited or no effect. 

True story

About 13 years ago in Park Royal in North West London a number of adjoining factories and other businesses suffered a series of night time break-ins over a period of 6 months.  The burglars would park nearby and walk along a rear private service road to the brightly illuminated backs of the factories where they would force their way in.  Even though the alarms went off they knew they would get at least 5 minutes for a bit of thieving and a quick getaway.  The service road was not overlooked, there was no passing traffic and so the only beneficiary of the light was the thieves.  Although the ultimate solution was to close and gate the private access road at night and to install low light CCTV cameras, for the next 4 months before that work was carried out the factory owners were advised by the police to turn off the rear security lights.  No burglary occurred after the lights were turned off.  The burglars probably couldn’t see what they were doing!

The benefits

Clearly there are lots of benefits to be had from outside lights, but from a security viewpoint it is probably limited to enhancing our feelings of safety, helping us investigate an incident outside the house, dealing with callers at the door and lighting up places that are in full view of the street and our neighbours (if we have some) in the hope that the illuminated criminal will be deterred.   Therefore it is important that we do install lights in the right places that are controlled in the right way.  The following paragraphs look at what we should be lighting and the types of light fittings and lamps we should be using.

To read on click the headings in the left-hand navigation column

Updated July 2017