Most people lavish attention on the front door and forget the back of the house entirely — which is exactly where burglars prefer to work. Around a fifth of break-ins come through a back or patio door, largely because the rear of a home is hidden from the street, giving an intruder time and cover. Big glazed doors look like the soft target, and older ones often are. The good news is that a modern patio, French or bifold door can be genuinely secure, and an old one can usually be upgraded cheaply. This guide covers all three, and the specific weak points each has.
It comes down to opportunity. The doors at the rear are out of sight of neighbours and passers-by; they tend to have large areas of glass; and on older designs the locking is often a single weak point. The two classic sliding-door attacks — lifting the panel off its track and prying the single latch — can take seconds and make little noise. The encouraging part is that each weakness has a cheap, specific fix, so you do not need to replace a door to make it hard to beat.
Sliding doors run on a single track and usually rely on one latch, which gives an intruder two openings. The first is lifting the panel out of its track — defeated by an anti-lift bolt or block fitted at the top of the track, which stops the panel rising. The second is forcing that single latch — defeated by adding a secondary lock: an auxiliary deadbolt, a foot bolt at the base, or a sturdy security bar laid in the track. Most of these fit without drilling, and together they turn the easiest door in the house into a stubborn one. If your patio doors are more than about ten years old, assume they need this attention.
An anti-lift device plus one secondary lock on an old sliding door — often well under the cost of a call-out, and frequently no drilling — converts the most vulnerable entry point in the house into one a burglar will walk away from.
French doors fail differently: they meet in the middle, and the slave (second) leaf is the weak one if it is only held by simple catches. The fix is to secure that leaf with shoot bolts top and bottom into the frame and head, ideally as part of a key-operated multipoint, so both leaves are pinned. A popular retrofit is a twin-handle locking device that clamps both internal handles together — highly visible, easy to fit and a genuine deterrent. And because the handles carry euro cylinders, fit anti-snap cylinders: a protruding standard cylinder can be snapped in seconds.
Bifolds have an undeserved reputation for being weak. In fact a well-specified bifold is often the most secure glazed option, because the panels lock together: the master door carries a multipoint lock, each panel has its own locking points engaging into multiple carriers, and the tracks include anti-lift features. An intruder has to defeat several locks at once rather than one. When buying, look for doors tested to PAS 24 (a recognised attack-resistance standard) and carrying Secured by Design accreditation, the police-backed mark — those are tested credentials, not marketing.
A strong lock on a pane that pops out in one blow is not much use. For real peace of mind specify or upgrade to laminated glass, which holds together when struck rather than shattering, buying time and making noise; toughened glass and applied security film help too. Glass and locks work as a pair — the lock stops the door being opened, the glass stops the door being bypassed. The same thinking runs through our wider home security checklist and our guide to how burglars actually break in.
Patio and French doors are often called out specifically in policy wording — insurers may require anti-lift devices, key-operated multipoint locks, or top-and-bottom bolts on these doors as a condition of cover. It is worth checking yours, because an upgrade that improves your security can also be the difference at claim time; our guide to locks and home insurance explains how that works.
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The rear doors are exactly the ones worth a professional eye, because the right fix depends on the door, the track and the frame. Every LocksmithLocal locksmith can assess your patio, French or bifold doors, fit anti-lift devices, secondary locks and anti-snap cylinders, and advise on glazing — turning the soft side of the house into the secure one. Find your local locksmith to arrange a look.
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