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PAS 24 Security Explained for Aluminium Doors and Windows
When choosing new aluminium doors or windows, most people think about style, energy efficiency and how much natural light they will bring into the home.
But security is just as important.
One term you may come across when comparing aluminium windows and doors is PAS 24. It is often mentioned in product specifications, building regulation guidance and security-rated glazing systems.
In simple terms, PAS 24 is a security standard that shows a window or door has been tested to resist common methods of forced entry.
For homeowners, architects, builders and developers, understanding PAS 24 can help you choose aluminium doors and windows that not only look good, but also provide tested protection.
What Is PAS 24?
PAS 24 is a UK security standard for doorsets and windows.
It sets out enhanced security performance requirements for products that are intended to resist attacks commonly associated with casual or opportunistic burglars. BSI describes PAS 24 as covering test methods and acceptance criteria for doorsets and windows intended to offer a level of security suitable for dwellings and similar buildings.
The standard applies to different materials, including aluminium, PVCu, timber and composite systems.
For aluminium windows and doors, PAS 24 helps demonstrate that the product has been designed and tested with security in mind.
What Does PAS 24 Test?
PAS 24 testing is designed to assess how well a window or door can resist attempted break-ins.
Rather than simply looking at one component, the test considers the complete product.
That can include:
For doors, PAS 24 usually refers to the complete doorset, not just the door leaf. This means the frame, hardware and locking system are all important.
For windows, it looks at how the window performs as a complete unit.
Why PAS 24 Matters
PAS 24 matters because a window or door is often one of the most vulnerable points in a property.
A strong-looking aluminium door is not automatically secure. The locks, glazing, frame design and installation all need to work together.
PAS 24 gives you reassurance that the product has been tested against recognised security requirements.
1. It Helps Protect Against Forced Entry
PAS 24 is designed to reflect the type of attack associated with opportunistic burglary. Secured by Design explains that the test is intended to mimic attack methods using tools that are easy to conceal.
This makes the standard especially relevant for homes, extensions, new builds and ground-floor glazing.
2. It Gives You a Clear Security Benchmark
Without a recognised standard, it can be difficult to compare the security of different aluminium doors and windows.
PAS 24 gives homeowners and specifiers a clearer way to understand whether a product has been tested to a recognised level.
3. It Supports Building Regulation Requirements
In England, Approved Document Q provides guidance on security in dwellings. It applies to new dwellings and covers reasonable standards for doors and windows to resist unauthorised access.
This is one reason PAS 24 is often discussed on new-build projects and residential developments.
4. It Can Support Secured by Design Requirements
PAS 24 is also closely linked with Secured by Design, the official police security initiative. Secured by Design provides guidance on security standards for doors, windows and glazing products.
While PAS 24 and Secured by Design are not exactly the same thing, they are often connected in security-focused specifications.
PAS 24 and Aluminium Doors
Aluminium doors are popular because they are strong, slim and modern. They are often used for large openings, garden access and contemporary home designs.
PAS 24 can apply to a range of aluminium door systems, including:
For large glazed openings, security is especially important. A wide sliding or bifold door can transform a living space, but it should also provide confidence that the opening is properly protected.
A PAS 24-tested aluminium door system will usually combine strong frames, secure locking points, suitable glazing and tested hardware.
PAS 24 and Aluminium Windows
PAS 24 can also apply to aluminium windows.
This is particularly important for windows that are easy to access, such as:
Aluminium windows can offer excellent strength and slim sightlines, but security still depends on the full system.
A PAS 24-tested aluminium window will usually include secure locking, suitable glazing, robust frame design and tested resistance against forced entry.
Does PAS 24 Mean a Product Is Burglar-Proof?
No product can be described as completely burglar-proof.
PAS 24 does not mean a window or door can never be broken into. Instead, it means the product has been tested to resist a recognised level of attack.
The aim is to make forced entry harder, slower and less attractive to an opportunistic intruder.
In many cases, burglars look for quick and easy access. A secure, tested aluminium window or door can help reduce that risk.
What Is the Current PAS 24 Standard?
The PAS 24 standard has been updated over time.
The current version commonly referenced is PAS 24:2022+A1:2024, which relates to enhanced security performance requirements for doorsets and windows in the UK. NBS lists PAS 24:2022+A1:2024 as current and notes that it includes test methods, classification, marking, design, installation and acceptance criteria.
When comparing products, it is worth checking which version of PAS 24 is being referenced and whether the certification applies to the exact product configuration you are buying.
PAS 24 vs Approved Document Q
PAS 24 and Approved Document Q are connected, but they are not the same thing.
PAS 24
PAS 24 is a product security standard. It focuses on the tested performance of doorsets and windows.
Approved Document Q
Approved Document Q is building regulation guidance for security in dwellings in England. It explains security requirements for certain new residential buildings.
In simple terms:
PAS 24 relates to the tested product.
Approved Document Q relates to building regulation guidance.
If you are working on a new-build project, your architect, builder, installer or building control provider can help confirm what is required.
PAS 24 vs Secured by Design
PAS 24 is a test standard for windows and doors.
Secured by Design is a wider police-backed security initiative covering products, design principles and crime prevention. Secured by Design references recognised standards for doors, windows and glazing, including PAS 24.
A product may be PAS 24 tested, Secured by Design accredited, or both, depending on the manufacturer and specification.
What Makes an Aluminium Door or Window Secure?
PAS 24 performance depends on more than one feature.
A secure aluminium system may include:
Multi-Point Locking
Multi-point locking helps secure the door or window at several points around the frame.
Strong Aluminium Frames
Aluminium is naturally strong, making it a popular choice for secure, slim-framed systems.
Secure Handles and Hardware
Locks, handles, hinges and cylinders all play an important role in security.
Suitable Glazing
The glass specification matters, especially for doors and accessible windows. Laminated glass is often used where enhanced security is required.
Tested System Design
PAS 24 is about the complete tested system, not just individual parts.
Professional Installation
Even a high-quality product needs to be installed correctly. Poor installation can weaken security, create gaps or affect performance.
Is PAS 24 Only Needed for New Builds?
PAS 24 is often discussed in relation to new-build homes because of Approved Document Q.
However, it can also be a useful standard for renovations, extensions and replacement projects.
Even where PAS 24 is not strictly required, many homeowners still choose security-rated aluminium windows and doors for extra peace of mind.
This can be especially valuable for:
Should You Ask for PAS 24 Certification?
Yes, if security is important to your project, it is sensible to ask whether the product is PAS 24 tested.
You can ask:
Is the product PAS 24 tested?
Check whether the system has been tested to PAS 24.
Which version of PAS 24 applies?
Standards are updated, so ask which version is referenced.
Does the certification apply to my exact product?
Performance can vary depending on size, style, glazing and hardware.
Is the glass specification included?
Security-rated glazing may be required for certain applications.
Is the installation included in the security specification?
Correct fitting is essential for the product to perform as intended.
Does PAS 24 Affect the Look of Aluminium Doors and Windows?
Not necessarily.
Modern aluminium systems can combine slim frames, large glass areas and strong security performance.
This means you can still achieve a clean, contemporary look while choosing products that are tested for security.
For many homeowners, aluminium is attractive because it offers a strong balance of:
Is PAS 24 Worth It?
For many projects, yes.
PAS 24 gives you a recognised way to compare security performance. It can support building regulation requirements, improve peace of mind and help protect your home against opportunistic forced entry.
It is especially worth considering for accessible windows and doors, large glazed openings and new-build homes.
Simple Summary: What Homeowners Need to Know
PAS 24 is a UK security standard for windows and doors.
It shows that a product has been tested to resist common methods of forced entry.
For aluminium doors and windows, PAS 24 can apply to the complete system, including the frame, glazing, locks and hardware.
It is particularly important for new-build homes, accessible windows, entrance doors, sliding doors and bifold doors.
A PAS 24-tested product is not “burglar-proof”, but it can make forced entry harder and provide valuable reassurance.
Choosing Secure Aluminium Doors and Windows With Nu-Scene
At Nu-Scene, we help homeowners, builders and developers choose aluminium windows and doors that combine style, performance and security.
Whether you are planning a new build, extension, renovation or replacement project, understanding PAS 24 can help you make a more confident decision.
If you are comparing aluminium doors or windows and want help with security specifications, our team can guide you through the options and recommend a system that suits your property, design and budget.
FAQs About PAS 24
What does PAS 24 mean?
PAS 24 is a UK security standard for doorsets and windows. It shows that a product has been tested to meet enhanced security performance requirements.
Does PAS 24 apply to aluminium doors?
Yes. PAS 24 can apply to aluminium doors, including entrance doors, sliding doors, bifold doors and other glazed door systems.
Does PAS 24 apply to aluminium windows?
Yes. Aluminium windows can be tested to PAS 24, especially where they are accessible or required for new-build compliance.
Is PAS 24 required for all homes?
Not always. It is often relevant for new-build homes and accessible windows and doors under Approved Document Q in England, but requirements vary by project.
Is PAS 24 the same as Secured by Design?
No. PAS 24 is a product testing standard. Secured by Design is a wider police-backed security initiative that recognises certain security standards and product accreditations.
Does PAS 24 mean a door is burglar-proof?
No. It means the door or window has been tested to resist a recognised level of attack. No product can guarantee complete protection, but PAS 24 can make forced entry more difficult.
Should I choose PAS 24 aluminium windows and doors?
If security is important, or if your project requires enhanced security performance, PAS 24-tested aluminium windows and doors are worth considering.
What Is a U-Value? A Simple Guide for Aluminium Doors and Windows
When you are comparing new aluminium windows or doors, you will often see the term U-value mentioned in brochures, quotes and technical specifications.
It sounds complicated, but the idea is simple: a U-value tells you how well a window or door keeps heat inside your home.
For homeowners, architects and developers, understanding U-values can make it much easier to compare products and choose the right glazing system for comfort, energy efficiency and long-term performance.
What Does U-Value Mean?
A U-value measures how quickly heat passes through a material or building element, such as a window, door, wall or roof.
For aluminium windows and doors, the U-value shows how much heat can escape through the complete unit. This usually includes the frame, glass, spacer bars and seals.
U-values are measured in:
W/m²K
That stands for watts per square metre per degree Kelvin. You do not need to remember the science behind it. The important thing is this:
The Lower the U-Value, the Better the Insulation
With U-values, lower is better.
A lower U-value means less heat escapes through your windows or doors. This can help your home feel warmer in winter, more comfortable throughout the year and potentially more efficient to heat.
For example, a high-performance aluminium window or door with a low U-value will usually retain heat better than an older single-glazed or poorly insulated system.
Why Do U-Values Matter?
U-values matter because windows and doors are a key part of your home’s thermal performance. Even a beautifully designed space can feel cold or inefficient if the glazing does not perform well.
Good U-values can help with:
1. Keeping Your Home Warmer
Efficient windows and doors help reduce heat loss, making rooms feel more comfortable during colder months.
2. Reducing Energy Waste
When less heat escapes, your heating system does not have to work as hard to maintain a comfortable temperature.
3. Improving Comfort Near Windows and Doors
Poorly insulated glazing can create cold spots around windows and doors. Better thermal performance helps reduce that uncomfortable chill.
4. Supporting Building Regulation Requirements
Energy efficiency is an important part of modern Building Regulations, and Approved Document L provides guidance on conservation of fuel and power in England.
5. Making Better Product Comparisons
Two aluminium doors may look similar, but their thermal performance can be very different. The U-value gives you a clearer way to compare them.
What Is a Good U-Value for Aluminium Windows and Doors?
A “good” U-value depends on the type of product, the glazing specification, the building design and whether the project is a new build, renovation or replacement.
As a general rule, modern double-glazed and triple-glazed systems perform much better than older glazing. Some window companies explain that U-values can refer to the centre pane of glass only or to the whole window, with the whole-window U-value giving a more realistic view of performance.
When comparing aluminium windows and doors, make sure you are looking at the whole product U-value, not just the glass.
Whole Window U-Value vs Glass U-Value
This is one of the most common areas of confusion.
A glass unit might have a strong thermal performance figure, but that does not always tell the full story. The complete window or door also includes the aluminium frame, thermal breaks, gaskets, spacers and overall design.
Glass U-Value
This refers mainly to the insulated glass unit.
Frame U-Value
This measures the thermal performance of the frame material.
Whole Window or Door U-Value
This gives a more complete picture because it considers the entire product.
When choosing aluminium windows and doors, the whole unit U-value is usually the figure to pay closest attention to.
Are Aluminium Windows and Doors Energy Efficient?
Yes, modern aluminium windows and doors can be highly energy efficient.
Older aluminium systems were sometimes associated with heat loss because aluminium naturally conducts heat. Modern systems solve this with thermal breaks.
A thermal break is an insulating barrier inside the frame that helps reduce heat transfer from inside to outside. Combined with high-performance double or triple glazing, modern aluminium systems can offer excellent thermal performance while keeping the slim frames and contemporary appearance that aluminium is known for.
What Affects the U-Value of Aluminium Windows and Doors?
Several factors can influence the final U-value of a window or door.
1. The Glazing Type
Double glazing and triple glazing usually perform much better than single glazing. The glass specification, cavity width and gas fill can all affect performance.
2. Thermal Breaks in the Frame
A well-designed aluminium frame with a good thermal break can significantly improve insulation.
3. Spacer Bars
Warm edge spacer bars can help reduce heat loss around the edge of the glass unit.
4. The Size and Style of the Product
Large sliding doors, bifold doors, fixed windows and opening windows may all have different U-values depending on their design.
5. Installation Quality
Even a high-performance product needs to be installed correctly. Poor fitting can create gaps, draughts and thermal weak points.
U-Values and Aluminium Doors
For aluminium doors, U-values are especially important because doors often cover a large glazed area.
This is particularly true for:
If you are choosing large aluminium doors for a kitchen extension, garden room or open-plan living space, the U-value can have a real impact on comfort.
A lower U-value helps keep the room warmer and makes the glazed area feel more practical throughout the year.
U-Values and Aluminium Windows
Aluminium windows are often chosen for their slim sightlines, strength and modern appearance.
When combined with strong thermal performance, they can suit a wide range of homes, from contemporary new builds to period renovations where a clean, minimal look is required.
When comparing aluminium windows, ask for the U-value of the full window system and check whether the figure applies to the exact size and style you are considering.
Is a Lower U-Value Always Best?
In most cases, a lower U-value is better for reducing heat loss. However, it is not the only thing to consider.
You should also think about:
The best window or door is not just the one with the lowest number. It is the one that gives the right balance of performance, design, durability and value for your project.
Questions to Ask When Comparing U-Values
Before choosing aluminium windows or doors, it is worth asking:
Is this the whole product U-value?
Make sure the figure includes the frame and glass, not just the centre pane.
Does the U-value apply to my exact product?
Performance can vary depending on size, configuration and glazing choice.
Is the system compliant for my project?
Your installer, architect or building control body can help confirm what is required.
What other performance ratings should I consider?
You may also want to ask about security, weather rating, acoustic performance and glass specification.
Do U-Values Affect the Cost of Aluminium Windows and Doors?
Higher-performing aluminium windows and doors can sometimes cost more, especially if they use advanced glazing, improved thermal breaks or triple glazing.
However, the cheapest option is not always the best value. Better thermal performance can improve comfort, reduce heat loss and help future-proof your home.
For many homeowners, the right choice is a balance between appearance, performance and long-term value.
Simple Summary: What Homeowners Need to Know
A U-value tells you how well a window or door keeps heat in.
The lower the U-value, the better the insulation.
For aluminium windows and doors, you should look for the whole product U-value rather than just the glass value.
Modern aluminium systems can be very energy efficient thanks to thermal breaks, high-performance glazing and quality installation.
Choosing Aluminium Windows and Doors With Nu-Scene
At Nu-Scene, we help homeowners, builders and developers choose aluminium windows and doors that look great and perform well.
Whether you are planning a new build, renovation, extension or replacement project, understanding U-values can help you make a more confident decision.
If you are comparing aluminium windows or doors and want help understanding the options, our team can guide you through the specification and recommend a solution that suits your home, style and budget.
FAQs About U-Values
What does a U-value measure?
A U-value measures how much heat passes through a building element, such as a window or door. For glazing, it helps show how well the product insulates.
Is a lower U-value better?
Yes. A lower U-value means less heat is lost, which usually means better insulation.
Are aluminium windows energy efficient?
Modern aluminium windows can be highly energy efficient, especially when they use thermal break technology and high-performance glazing.
Should I compare glass U-values or whole window U-values?
You should usually compare whole window or whole door U-values because they include the frame and glass together.
Do U-values matter for bifold and sliding doors?
Yes. Large glazed doors can have a big impact on comfort and heat loss, so U-values are an important part of the specification.
Bifold, Slider, or French Doors: Which Option Fits the Project Brief Best
Choosing the right door system is not always about which product looks best in a brochure.
For installers, builders, and trade buyers, the better question is usually: which option fits the project brief best? The answer will depend on the type of property, the available opening, how the space will be used, and what matters most to the client — whether that is budget, access, appearance, ventilation, or wide uninterrupted views.
Bifold doors, sliding doors, and French doors all have their strengths. The key is matching the product to the job, rather than forcing the job to suit the product.
Here is a practical guide to where each option tends to work best.
Start with the brief, not the product
Before recommending any door system, it helps to step back and look at the full brief.
Ask questions such as:
Once those points are clear, it becomes much easier to work out whether bifold, sliding, or French doors are the right fit.
When bifold doors suit the project best
Bifold doors are often the strongest option when the client wants to open up a large section of the rear elevation.
Because the panels fold and stack to one or both sides, they can create a wide opening between inside and outside. That makes them especially popular on kitchen extensions, family homes, and garden-facing living spaces where the goal is flexibility and a strong indoor-outdoor connection.
Bifold doors are often a good fit for:
They are particularly useful where the client wants the choice between opening one panel for everyday use or folding the whole system back for entertaining and warmer weather.
Things to consider with bifolds
Bifold doors are not always the best answer for every project.
Because the panels stack, they do introduce more frame lines than a large sliding door. They also need room for the panels to fold back, which may affect furniture layout or usable space near the opening.
That means they may be less suitable where:
Bifolds are often the practical all-rounder, but they are not always the cleanest visual solution.
When sliding doors suit the project best
Sliding doors are often the strongest choice when the priority is glass, light, and a more minimal look.
With fewer vertical frame lines and larger glass panels, they tend to suit contemporary designs particularly well. They are a popular option for modern extensions, luxury builds, and projects where the client wants to frame a view rather than open the entire wall.
Sliding doors are often a good fit for:
In many cases, sliders suit clients who want a sleek, architectural feel and are happy with a partial opening rather than having the whole aperture open at once.
Things to consider with sliders
Sliding doors do not open in the same way as bifolds.
Because one panel slides behind another, part of the opening always remains covered. That is not a problem on many projects, but it can matter if the client expects the opening to feel completely open in summer.
They may be less suitable where:
Sliding doors often win on sightlines and design simplicity, but not always on full opening flexibility.
When French doors suit the project best
French doors remain a very useful option, especially on smaller, more traditional, or more budget-conscious projects.
They are simple, familiar, and often work well where the opening is not especially wide. They can also suit properties where the customer wants a straightforward garden door rather than a feature glazing system.
French doors are often a good fit for:
For many customers, French doors offer the right balance of function, appearance, and cost without adding unnecessary complexity.
Things to consider with French doors
French doors are not usually the best option where the goal is to create a wide glazed feature.
Compared with bifolds or sliders, they generally offer:
They are practical and cost-effective, but they are rarely the standout choice for bigger design-led projects.
Which option works best by project type?
Looking at the project type often gives the clearest answer.
Extensions
For rear extensions, bifold and sliding doors are usually the main contenders.
If the client wants flexibility, wide opening access, and strong connection to the garden, bifolds are often the better fit. If the priority is a cleaner glazed look with larger panes and slimmer sightlines, sliding doors may suit the brief better.
French doors can still work on smaller extensions, but on larger openings they are usually the less suitable option.
Rental properties
For rentals, the best choice often comes down to durability, practicality, and budget.
French doors are often a sensible solution here because they are simple, familiar, and cost-effective. In some higher-end rental properties, a slider may help create a stronger visual appeal, but in many cases a straightforward French door set meets the brief more efficiently.
Small patios
For smaller openings and compact patio areas, French doors are often the most natural fit.
They give easy access, suit a wide range of property styles, and avoid overcomplicating the opening. In some cases, a small bifold can work, but it will not always represent the best use of budget or space.
Family homes
For busy family homes, bifold doors often make a lot of sense.
They provide practical day-to-day access, plenty of ventilation, and the option to open the space fully when needed. A traffic door can also make them convenient for everyday use without folding the whole set each time.
That said, sliders can also work well in family homes where the client is more focused on views and natural light than on having the full opening clear.
Luxury builds
For premium projects, sliding doors are often the most natural match.
They suit larger glazed openings, deliver a more contemporary look, and create the kind of clean visual finish many luxury clients want. Bifolds can still work on high-spec homes, especially where usability and opening width are priorities, but sliders tend to align more closely with a sleek architectural brief.
Budget-sensitive jobs
Where budget matters most, French doors are often the most efficient option.
They can deliver a neat and practical result without the cost of a larger feature-door system. Bifolds may still be viable depending on the size and specification, but sliders are often harder to justify on price-led projects unless the design brief specifically calls for them.
The right product is the one that suits the job
There is no universal winner between bifold, sliding, and French doors.
Each system has strengths, and each can be the right answer when matched to the correct project brief. Bifolds tend to suit flexible family living and wider openings. Sliders are often best for modern, design-led spaces where glass and views matter most. French doors remain a strong option for smaller openings, traditional homes, and budget-conscious jobs.
For installers and trade buyers, the most useful approach is to guide the customer based on how the space will actually be used — not just on which door style is currently getting the most attention.
Because when the product fits the brief, the whole project tends to work better.