I was asked by a concerned citizen if it was okay to protect your house or property with an electric fence. Now, this is a very dangerous question: if I gaily said, yes, no problem, then it is possible that the person asking would end up killing somebody and the defence offered would be that a professional engineer said it was okay.

Thus, I said that all electric fences were subject to a SANS standard (SANS 60335-2-76) and that an electrical certificate of compliance is mandatory.

But are electric fences a good idea? It is a simple fact that they are fairly easy to defeat if you know how to, and it is also a fact that the people who do know how are most likely to try to rob you.

So, in this piece, I am going to give some ideas about how to defend your home that do not involve killing somebody on the boundary fence.

First, lights. It’s a good idea to make people who are watching your property believe that you are home when you are not. In this regard, just fit two of your (nonfluorescent) light circuits with a programmable controller such as a Bikkel. This is a dimming module which is programmed by a series of pulses from a switch or push button. The one I have is ten years old, so I am not sure my description of the current units is accurate, but this is how it works: you program it to switch on the lights in any given circuit at random intervals. This gives the impression of somebody going into and out of a room and switching on the lights and then off when they leave the room. Very convincing. Next: we all know that you get those lights which switch on with movement detection. Connect up two of these to the front and back of your house. Now, the trick is this: do not set them so that they turn on the moment there is movement outside. Set a delay of about five seconds between detection and the light switching on. It gives the impression to the intruder that they have been spotted and the householder has switched on the lights.

You can turn regular lights into motion sensor lights by switching to motion-sensing lamps. One can attach a sounder to the circuit so that it gives a little beep-beep on detection and then, after a five-second pause, the lights come on. A just audible beep-beep is much better than a louder one – it’s more unsettling. It’s also a good idea to put a motion-sensing light inside your house.

There are other devices which rely on intruder detection and alarm. However, these also require a reaction to the alarm, and require that you pay for a reaction security force. This is a different topic.

Moving on to nonelectrical defence, the following: the nonelectric, fake electric fence. This is as follows: you buy some 2.5-mm- diameter stainless steel rigging wire from a boating shop and some turnbuckle shackles. Buy some angle shelving brackets (one pair every 5 m) and some electric fence insulators. Fix the angle brackets on top of the wall and thread the rigging wire through the insulator – don’t cut it. So, to all appearances, the rigging wire is in fact strained off the insulators but it’s not – using the turnbuckles strain either end of a solid point (steel post, brickwork rawl bolt, etc). Then: when the intruder sees the ‘fence’, an attempt will be made to cut the wire. Which can’t be cut. They’ll try to throw a blanket and climb over. This will not work because the wire will not break. Ultimately, they get caught up in the wire and trip over the wall or fence (if you need a sketch of the idea, email me). But on behalf of Tommy, Sophie and Mika, I have to mention one of the best intruder defences: dogs. Which they are. Woof! Woof!