Are Patio Doors a Security Risk? Here’s the Truth
Big glass doors can completely change a home.
They bring in more daylight, open up views of the garden and create that connection between inside and outside that so many homeowners want.
But they also raise one very understandable question:
Are patio doors secure?
After all, if you’re replacing part of a solid wall with a large area of glass, isn’t that potentially giving someone an easier way into your home?
The reassuring answer is that a good-quality modern patio door can be extremely secure.
But – and this is important – not all patio doors are the same.
The security of a door isn’t determined simply by whether it’s made from uPVC or aluminium, or even by how thick the glass looks. It comes from the way the whole doorset has been designed, manufactured, glazed, locked and installed.
So, if you’re considering new doors to your garden, here’s what we’d suggest looking for.
First, what do we actually mean by “patio doors”?
People use lots of different names for them.
You might call them:
- patio doors
- sliding patio doors
- sliding doors
- bifold or bi-fold doors
- French doors
- garden doors
- doors to the garden
- doors to the patio
- doors onto the decking
Technically, these aren’t all the same type of door.
A sliding patio door usually has large glazed panels that slide horizontally along a track.
Bifold doors have several panels that fold and stack together, allowing you to open up a much larger proportion of the opening.
French doors are a pair of hinged doors that open from the centre.
And then there are Heritage or steel-look doors, with slim frames and glazing bars inspired by traditional steel designs.
But from a homeowner’s point of view, they often perform the same basic job: they’re the large external doors between your home and your garden, terrace, balcony, patio or decking.
And whatever you call them, they need to be secure.
So, are patio doors secure?
Yes – modern patio doors can be very secure, provided you choose a properly designed, manufactured and installed system.
Older patio doors are partly responsible for the reputation these doors have for being vulnerable.
Some older sliding doors had relatively basic locks and tracks that could potentially be attacked or manipulated. Police security advice still recommends checking older sliding patio doors for features such as anti-lift protection because vulnerable doors may potentially be lifted from their runners.
Modern security standards have moved on considerably.
Today, when we’re assessing the security of a patio door, we’re interested in the whole doorset:
the frame + glass + locks + hinges or tracks + hardware + construction + installation.
A strong lock fitted to a weak door doesn’t make a secure doorset.
Likewise, very strong glass doesn’t compensate for inadequate locking or poor installation.
Everything has to work together.
What is PAS 24 - and why should you look for it?
This is probably one of the most useful things to understand when buying new external doors.
PAS 24 is a recognised UK security standard for doors and windows.
Rather than relying on a manufacturer simply describing a product as “secure”, PAS 24 provides a defined method for testing doorsets and windows against methods of attack associated with an opportunistic burglar.
Importantly, PAS 24 isn’t just about testing a lock in isolation.
It’s about the performance of the doorset as a whole.
The current standard covers different types of doorsets including hinged, sliding and folding-sliding doors.
At DDG Windows™, we manufacture PAS 24-compliant uPVC products as part of our range. Not every door or configuration carries PAS 24 certification, so if this is an important requirement for your home, talk to us when you’re choosing your doors and we can advise you on the appropriate specification.
Whether or not you’re specifically looking for PAS 24, the principle behind it is a useful one when buying any external door: security isn’t about one impressive lock or one strong piece of glass. It’s about how the complete doorset performs.
Security shouldn’t be an afterthought on the door that protects the back of your home. It should be considered from the beginning.
What actually makes a patio door secure?
There isn’t one magic component.
Good patio-door security comes from several features working together.
1. Multi-point locking
Modern external doors typically don’t rely on one simple locking point.
Multi-point locking systems secure the door at several positions around the frame.
Depending on the door system, that can include hooks, bolts and other locking points which engage when the door is locked.
This makes it much more difficult to attack one particular point of the door.
It’s particularly important on large glazed doors because of their size.
2. A strong, well-made frame
The frame matters just as much as the lock.
Modern uPVC patio doors use engineered profiles designed to provide rigidity, insulation and security.
Modern aluminium patio doors use strong aluminium profiles that can support large panes of glass while maintaining relatively slim sightlines.
Neither material should be judged on its own.
A well-designed PAS 24 uPVC doorset can be highly secure, just as a properly engineered PAS 24 aluminium doorset can be highly secure.
The quality of the complete system is what matters.
3. Secure tracks and hardware
Sliding doors have different security considerations from hinged doors.
With older sliding patio doors, one concern was whether a door could potentially be lifted or manipulated from its track.
Modern systems can incorporate anti-lift measures, secure locking mechanisms and much more sophisticated running gear.
Police home-security advice specifically highlights anti-lift protection as something homeowners with sliding patio doors should consider.
4. Good installation
Even an excellent door needs to be installed correctly.
The doorset needs to be securely fixed into the building, correctly aligned and adjusted so the locks engage as they were designed to.
It’s one reason we believe manufacturing and installation shouldn’t be treated as completely separate parts of the process.
At DDG Windows™, our doors are made to measure and installed by our own experienced teams.
We know the product we’re fitting because we’re involved in making it.
What about all that glass?
This is usually the next question.
“Surely somebody can just smash the glass?”
Modern patio-door glazing is very different from the thin single panes found in many older doors.
There are also several different types of glass, and they do different jobs.
Understanding the difference helps.
Toughened glass
Toughened glass is a type of safety glass.
It undergoes a heat-treatment process which makes it significantly stronger than ordinary annealed glass and changes the way it behaves if it breaks.
Rather than breaking into large, dangerous shards, toughened safety glass is designed to break into much smaller pieces.
This is particularly important in doors and other areas where people could fall against the glass.
However, it’s worth making an important distinction:
Safety glass and security glass aren’t necessarily the same thing.
Toughened glass is primarily designed around strength and safe breakage.
If enhanced resistance to deliberate attack is required, laminated security glass may also be specified.
Laminated glass
Laminated glass works differently.
Layers of glass are bonded together with an interlayer. If the glass breaks, the interlayer helps hold the broken glass together.
Certain laminated glazing can also be tested and classified for resistance to manual attack.
That can make laminated glass particularly useful where additional security is a priority.
The right specification depends on the doorset, its location and the security performance required.
Double glazing
Most homeowners choosing modern patio doors will be looking at double-glazed units.
Two panes of glass are separated by a sealed cavity, creating an insulating glass unit.
This isn’t just about security.
Double glazing significantly improves thermal performance compared with the old single-glazed patio doors still found in many British homes.
And that difference can be particularly noticeable when you’re talking about several square metres of glass across the back of a house.
Triple glazing
Some modern door systems can also accommodate triple glazing.
As the name suggests, this adds another pane and another insulating cavity.
Depending on the complete doorset specification, triple glazing can improve thermal performance further and can also help with acoustic performance.
It doesn’t automatically make a door “more secure”, though.
Again, security depends on the specification and performance of the whole doorset rather than simply counting panes of glass.
Low-E glass
Another term you may come across is low-emissivity or Low-E glass.
This has a specialist coating designed to reduce heat loss by reflecting heat back towards the interior while still allowing daylight through.
If you’re replacing old single-glazed garden doors, this type of glazing technology can make an enormous difference to how the room feels during colder weather.
Tinted and solar-control glass
Large areas of glass can also create another problem: too much heat from the sun.
For south-facing rooms, large extensions and very wide glazed openings, solar-control glass can help reduce solar heat gain while still allowing plenty of daylight into the room.
Tinted glass is another option. Depending on the specification, it can reduce glare, provide a particular appearance and offer a degree of solar control.
Tinted glass can also be incorporated into insulating glass units and can be toughened or laminated where required.
So when choosing glass for large patio doors, the conversation isn’t simply:
“How thick is the glass?”
It’s:
What do we need this glass to do?
Security?
Safety?
Thermal insulation?
Solar control?
Noise reduction?
Privacy?
Or a combination of several of these?
That’s where getting the specification right really matters.
Are sliding patio doors secure?
Modern ones can be.
Sliding patio doors had something of a security problem historically because some older systems could be vulnerable around their tracks and locking mechanisms.
That’s one reason you’ll still see advice online about adding extra locks or anti-lift devices to old patio doors.
A modern PAS 24 sliding doorset is a very different proposition.
The locking system, frame, glazing, tracks and hardware are designed to work together as a secure external doorset.
At DDG Windows™, our aluminium sliding doors combine large expanses of glass and slim frames with modern locking and security performance.
So you can have the uninterrupted garden view without assuming that a large pane of glass means compromising the security of your home.
Are bifold doors secure?
They can be extremely secure.
People sometimes look at all the individual panels and hinges of a bifold door and assume that more moving sections must mean more weak points.
But again, it comes down to engineering.
A high-quality modern bifold system is designed as one complete doorset, with the panels, locking system, hinges, running gear, glazing and frame all working together.
DDG Windows™’ external bifold systems meet PAS 24 security standards.
Our IconiK F80 Slim aluminium bifold, for example, combines slim 87mm sightlines with concealed locks and security hardware.
Slim doesn’t have to mean vulnerable.
Are French doors secure?
Modern French doors can also offer excellent security.
Traditional French doors have two hinged leaves meeting in the middle, which can make people wonder whether that central meeting point is inherently weaker.
With a properly engineered modern system, security is designed around that configuration.
Multi-point locking and secure hardware help the two leaves work as part of a complete secure doorset.
Again, the specification matters much more than the name.
What about Crittall-style and Heritage doors?
The steel-look aesthetic has become hugely popular again, particularly in London homes.
You’ll often hear people call all slim, black-framed glazed doors “Crittall doors”, although Crittall is actually a specific manufacturer of steel windows and doors.
The broader terms are steel-look, Crittall-style or Heritage doors.
At DDG Windows™, we manufacture our Heritage range in aluminium.
It gives homeowners those elegant slim sightlines and distinctive glazing bars associated with traditional steel doors, but with modern glazing, weather sealing, thermal performance and security.
That makes them particularly interesting for period properties.
What if you have old wooden or single-glazed patio doors?
Across East London, North London and Essex, there are still plenty of Victorian and Edwardian homes with older timber French doors or garden doors.
And we completely understand why people keep them.
They can look beautiful.
Original timber, narrow glazing bars and traditional proportions can be an important part of the character of a period property.
The problem is that an older door may no longer perform particularly well.
Depending on its age and condition, you may have:
- single glazing
- relatively basic locks
- ageing hinges or hardware
- warped or deteriorating timber
- draughts around the frame
- poor weather seals
- significant heat loss
If you love the appearance, replacing it doesn’t have to mean putting in a chunky white modern door.
There are now much better ways to retain that character.
Heritage aluminium: traditional look, modern performance
Our Heritage aluminium doors are one option.
They recreate the slim, steel-inspired appearance many homeowners want while incorporating modern glazing, secure locking, weather sealing and thermal performance.
They work particularly well with Victorian and Edwardian properties where the homeowner wants to respect the architecture but doesn’t want to live with the compromises of an ageing single-glazed door.
Coloured uPVC can work too
Don’t rule out uPVC simply because you’re working with an older property.
Modern uPVC is available in far more colours and finishes than the standard bright-white frames many people remember.
With the right colour, proportions and detailing, a modern uPVC French or patio door can sit very comfortably within a traditional home while providing much better security, insulation and weather performance than an old single-glazed door.
It can also be a more cost-conscious alternative to aluminium.
The important thing is finding the solution that works with the house rather than forcing the house to fit the product.
Don't forget energy efficiency
Security may be the reason you started reading this guide, but if you’re replacing older patio doors, energy efficiency deserves just as much attention.
Large glazed doors account for a significant area of the external envelope of your home.
If they’re old, single glazed, poorly sealed or draughty, you’ll often feel it.
Modern double or triple glazing, Low-E coatings, insulated frames, thermal breaks and modern weather seals can dramatically improve the thermal performance of a doorset.
And that matters right now.
From 1 October 2026, Ofgem’s energy price cap increased by 4% for a typical household using electricity and gas and paying by Direct Debit.
So, while nobody should replace perfectly good doors simply because energy prices move up or down, replacing very old, draughty or single-glazed garden doors can improve comfort and reduce unnecessary heat loss.
If you’re already replacing the doors for security, renovation or aesthetic reasons, it makes sense to consider their thermal performance at the same time.
uPVC or aluminium patio doors: which is more secure?
This is a question we’re asked a lot.
Our answer is:
Don’t choose between uPVC and aluminium on security alone.
Both can provide excellent security when they’re part of a properly engineered and tested doorset.
Instead, think about the other differences.
uPVC can offer excellent insulation, security, low maintenance and value, with a much wider choice of colours and finishes than many homeowners realise.
Aluminium provides exceptional structural strength with much slimmer profiles, which makes it particularly suited to large glazed openings where you want maximum glass and minimal frame.
For many homeowners, the decision is therefore more about appearance, opening size, sightlines, budget and the character of the property.
Whichever material you choose, we’d put proven security performance much higher up the checklist than simply choosing one material over another.
So, are patio doors a security risk?
They don’t have to be.
An old, poorly maintained or inadequately secured patio door can certainly become a weak point in a home.
But it’s misleading to assume that large glass doors are automatically less secure.
Modern patio doors can combine:
- large areas of glass
- slim frames
- multi-point locking
- secure glazing
- anti-lift protection where appropriate
- strong frames and hardware
- excellent thermal performance
- PAS 24-tested security
And that’s really the point.
You shouldn’t have to choose between light, design and security.
A well-designed modern doorset should give you all three.
Our advice after more than 41 years
We’ve been manufacturing and installing windows and doors since 1983.
During that time, we’ve watched patio doors change enormously.
We’ve gone from relatively simple timber and early uPVC sliders to huge aluminium glass panels, slim bifolds and Heritage systems that would have been difficult to imagine when we started.
But the basic advice we’d give a homeowner hasn’t really changed:
Don’t judge a door by how it looks in a brochure. Ask how it’s made, how it’s glazed, how it locks, what security standard it meets and who is going to install it.
At DDG Windows™, every external patio and garden-door system we currently sell meets PAS 24 security standards.
Whether you call them patio doors, sliding doors, bifold doors, French doors or simply the doors out to the garden, they have an important job to do.
They should open your home to the garden.
Not to anyone else.
Patio Door Security FAQs
Modern patio doors can be highly secure when the complete doorset is properly designed, tested and installed. Look at the locking system, glazing, frame, hardware and recognised security standards such as PAS 24 rather than judging security purely by the amount of glass.
Older sliding doors can have vulnerabilities, particularly if they have basic locks or inadequate protection against being lifted from their tracks. Modern PAS 24 sliding doors are designed and tested to provide much greater resistance to opportunistic attack.
PAS 24 is a UK standard that sets enhanced security performance requirements for doorsets and windows. It uses defined testing and acceptance criteria intended to assess resistance to methods associated with opportunistic burglary.
Yes, high-quality modern bifold doors can be very secure. Look for a tested complete doorset with appropriate locking, strong hardware, secure glazing and professional installation.
Modern French doors can provide excellent security. The two-door configuration needs to be properly engineered, with suitable locking and hardware securing the doors into the frame.
No glass should simply be described as “burglar-proof”. Toughened glass is primarily a safety glass and is significantly stronger than ordinary annealed glass. For enhanced resistance to deliberate attack, laminated security glazing can be specified.
Certain types of laminated glass are designed and tested to provide resistance to manual attack. The interlayer also helps hold the glass together after breakage. The appropriate glazing specification will depend on the doorset and level of security required.
Double glazing alone doesn't determine how secure a patio door is. Security depends on the complete doorset - including the type of glass, frame, locks, hardware and construction.
Not automatically. Triple glazing adds another pane and insulating cavity and can provide excellent thermal and acoustic performance, but the security of the door still depends on its complete tested specification.
Both aluminium and uPVC doors can provide high levels of security. Rather than assuming one material is safer, look for the security performance of the complete doorset and standards such as PAS 24.
There isn't one style that is automatically the most secure. Sliding, bifold and French doors can all provide excellent security when designed and tested as complete secure doorsets. Look for PAS 24 compliance, suitable glazing, robust locking and high-quality installation.
Age alone doesn't mean a door must be replaced. But if your existing doors are single glazed, draughty, difficult to lock, deteriorating or no longer closing correctly, it's worth having them assessed. Modern replacements can provide significant improvements in security, comfort and thermal efficiency.
Absolutely. Modern Heritage aluminium and coloured uPVC systems can recreate traditional proportions and styles while incorporating modern glazing, locking, weather sealing and security. This can be particularly useful when replacing ageing timber or steel-style doors in Victorian and Edwardian properties.