The Crime Prevention Website


Answering the door to callers

Before we look at the different types of door controlling mechanisms let’s first consider how we should deal with callers at the door. This matter used to come up time and again at Neighbourhood Watch meetings!

In response to a call at the door the first thing you should do is peer through the door’s glazed panel or the door viewer (if you have obscured glazing) or a window to look at the caller (see also Door viewers and Secure vision panels ). If it’s a friendly face then you’ll open the door as usual; obviously.  If it’s a stranger then you should acknowledge the call, because not doing so could suggest that you are not at home, which may not be a good idea. 

What do you do next?  My mum, who’s pretty fit, pops upstairs to the front bedroom and opens the window and enquires about the caller’s business from there.  This normally brings the call to a speedy conclusion.  My Aunty Flo, who lives in a flat and cannot look through a window at the caller, has a conversation through the door, well in fact through the letter plate!  Not the friendliest approach I suppose, but she’s happy with it and that’s what counts.  After all, these are generally unsolicited calls from people who want to sell you something and you are not obliged to speak to them if you don’t want to.  So what if you think you are being a tad rude?

If Aunty Flo does need to open the door she puts on the chain and also puts a rubber door stop onto the floor a few centimetres back from the door.  This means that the door opens with the chain and onto the door stop.  She puts her foot firmly behind the door stop and opens the door, knowing full well that it would be very difficult to force the door open any further.

One of the drawbacks of the door chain or limiter is that some people treat it like a door lock.  In other words they think it should be on all the time and then take it off when they answer the door! 

In my book, Home Security – the complete handbookI talk about making a ‘Granny’s Boot’ or I suppose it could equally be called a ‘Granddad’s boot’.  This is a wooden wedge attached to a broom handle, which is placed behind the door.  When the door opens it hits the wedge and cannot open any further.  For wooden floors it’s probably a good idea to glue some rubber on the base to stop it from slipping.  The beauty of this contraption is that there’s no bending down and it can live in the umbrella stand.

For LOTS more information about checking the identity of a caller please see  Personal Security, Bogus callers (Distraction burglary)

Door chains and limiters

There are two schools of thought about the fitting and use of door chains and limiters and this is something that you’ll have to make your own mind up about having considered the previous and following paragraphs. They are generally for use on an inward opening door.

Consider this scenario:  You have a secure PAS 24:2012 doorset, which has been designed to keep intruders out and you’ll know that it’s been thoroughly tested to make sure that it does.  Or you have a timber door to which you’ve made lots of security improvements.  Then someone knocks on the door and what do you do?  You put the chain on and open the door.  The chain is held onto the door and the doorframe with some screws and whilst it may be well fitted will it provide as much security for you as the closed and locked door?  Probably not. 

So, even though we are not sure if door chains are actually safe why do we use them and why does the Home Office and some (but not all) police forces continue to recommend them?  I am afraid I don’t really know; it seems to be contrary to any logic, especially these days when many people have the benefit of very secure entrance doors.  It’s probably got something to do with not wishing to be rude to callers and a need to have that face to face conversation with a caller, rather than talking to them through the door.  It’s perhaps not ‘British’ to shout through doors!  The alternative view is that as most people just open the door without bothering to view the caller first, it is better to open the door on a chain than on nothing at all.  If the caller  is  up to no good the sight of the occupier putting on a door chain tells the caller that you are very much aware of your security and you won’t be an easy target.  

Door chains

Door chains are available in a wide variety of designs, but the majority of them are fixed to the door and the doorframe with a few screws, invariably in line with forces that could be applied by a criminal kicking or barging his way through the door. Use the longest screws you can and in some circumstances you might be able to fit the brackets with coach bolts, with the mushroom head on the outside of the door.  This hugely improved the strength of the fitting when I did this at my previous house.  

Lockable door chains

If you have an elderly relative who insists on leaving the chain on the door and you are worried that you won’t be able to get into their home in an emergency let them carry on doing this (because they will feel safer), but try to convince this person to fit a lockable door chain instead.  This one enables you to open the door with your keys as normal and then insert another key through the gap and into the cylinder on the door chain bracket to realise it.  You’ll often find this type of chain on a warden controlled flat.

Door limiters or Door bars


Door limiter or Door bar

These devices are somewhat stronger than door chains, but not necessarily the fittings.  Some of the better quality ones have some of the screws fitting at 90° to the force direction and, as with door chains, I would attempt to use the longest screws possible and coachbolts if the door and frame permit their use.

I've had several enquires about the door limiter above (couldn't find it on the net) and I've managed to find one at this link

Door cables

I have not been able to find these products on sale, but at one time you could by a plastic covered, high tensile steel cable which stretched across the back of the door between fittings that were bolted into the walls on either side of the doorframe.  The cable would spend most of its time dangling on the wall on the lock side of the door and all you needed to do when answering the door was to hook the other end onto its bracket on the other side of the door.  In demonstration they looked a lot better that the ordinary door chain and limiter.  If you can’t find them then this is something you could probably make for yourself.  If you can find one on sale please inform me and I’ll bring it to everyone’s attention.

Alarmed door chains with DNA spray

A fairly recent entry into the market of door chains is one that activates a screeching alarm if the thief attempts to force the door while opened on the chain and at the same time it sprays the intruder with a liquid containing a DNA trace chemical that is unique to your house.  Should the intruder be caught later they can link the DNA in his clothes back to your home providing the police with good evidence to prosecute.

Robert Simpson                                                                                         Managing Director StranDNA (UK) Limited

There are many thoughts travelling through a criminal’s mind prior to committing an offence! One of these thoughts is NOT getting caught!

Chain Reaction DNA is a new ‘police approved’ door security product that has been designed to ease the fear of burglary and at the same time give burglars more food for thought! The threat of being forensically linked to a crime scene being the ultimate deterrent!

As homeowners, the steps we take concerning home security will determine whether we become a victim of crime! The harder you make it for a criminal to gain access into your home, through the installation of alarms and other home security products, the lower the chance will be.

Chain Reaction DNA has been designed to ease the fear associated with doorstep crime and to deter burglaries, forced entries or home invasion robberies, but if activated it will sound an ear piercing, high decibel, alarm to draw attention to the fact that unlawful entry is being attempted.  At the same time the attacker will be sprayed by the latest UV based forensic trace technology. This liquid fingerprint stains the would-be intruder for weeks and the substance is easily identified by the Police using UV lighting technology!

Our goal is to turn the tables on the criminal with the threat of being forensically linked to a crime scene, thereby deterring the offender in the first place.

Chain Reaction DNA has been installed and the forensic component registered to numerous homes and businesses throughout the UK and has also been deployed in domestic violence applications.  StranDNA are pleased to say that not one of the target hardened addresses using our product has suffered a re-offence or unlawful entry since its application leading us to believe the deterrent value is working!


Standards for door chains

To be helpful, The Door and Hardware Federation (DHF) have produced a technical specification entitled TS003 Selectively applied door opening restrictors for security purposes 2005, which recommends the level of performance that door opening restrictors should achieve in order to ensure the safety of users.  The problem I have is that in spite of a lot of searching of the web I cannot find a single door chain that has been tested to this specification.  That is not to say there isn’t one; it’s just that I cannot find it.  As soon as I have heard back from the DHF I will update this section, because I am sure you would agree it would be better to buy something that you know will meet a performance standard than not.  That said, it all rather depends on what you install the fittings into. 

Sold Secure, a test house owned by the Master Locksmiths Association, test door chains and it may be worth visiting their site to see if they have any listed.