What to consider before buying aluminium, PVCu or timber windows

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Nick Dardalis

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When it comes to new windows and doors for the home, the choices are aluminium, PVCu or timber windows.  With different materials and brands of windows, what is the best window material for your home? In this article, we help you by focusing on the essential aspects of aluminium, PVCu or timber windows.  We will explain aesthetics, security, maintenance, features and cost.

First of all, there are a few things to consider when researching what the best material for your new windows and doors is.  If you are replacing your existing windows, you have to decide if you want new windows in the same style and colour.  Alternatively, you may be thinking of changing the entire appearance of the house and choosing a different type of window in a new colour as well.

Besides window style and colour, think about ventilation through the right size window vents.  A means of fire-escape on upper floor windows is vital as well.

Why does it matter what aluminium, PVCu or timber windows are made of?

For new build houses and extensions, you have more flexibility and freedom. With the current trend of extending our homes and creating modern extensions, your windows may need to work sympathetically with new aluminium bifolding doors or the latest contemporary sliding doors.

The good news is that aluminium, plastic and timber windows now come in a diverse range of styles and types to work with any age or type of house.  Some materials offer you less choice as we explain later on in this article.

aluminium, pvcu or timber windows

Beware the myths around PVCu, timber and aluminium windows.

It is important to ensure you are reading factual and correct information about these three very different window materials.  Because some aluminium websites try to dissuade you from having timber or upvc, they can give the impression that choosing these options will cause you inconvenience. As a result, they may say things like high maintenance or a substandard product through weakness.  This information is frequently incorrect. 

Likewise, some PVCu websites continue to point to weaknesses in aluminium windows that are no longer relevant with current products. Every window material has its good and bad points depending on where you fit it and the intended use. Here are some of the common myths you will read about aluminium, PVCu or timber windows.

Aluminium Myth

PVCu Myth

Timber Myth

Aluminium Windows Condensate

PVCu windows warp and twist

Timber windows need constant maintenance

Aluminium windows are entirely maintenance free

PVCu windows look cheap

Timber windows are too expensive

Aluminium windows are only for commercial buildings

PVCu windows are not secure

Only traditional windows are available

Aluminium windows are not energy efficient

PVCu windows are weak

Engineered timber will warp

Aluminium windows rust or corrode

PVCu windows stick

Timber suffers from sunlight and water ingress

You can’t repair aluminium windows

PVCu windows are mass produced

Timber windows are heavy and hard to use

Aluminium windows only come as casements

PVCu windows are not environmentally friendly

Timber windows are not suitable for sunny elevations

Our article comparing PVCu and aluminium bifolding doors points out that substantial businesses are behind PVCu.  The same applies to timber windows.  

Systems companies for all three materials are professional organisations, many of which operate all over the world.  As a result, all windows in aluminium, PVCu or timber meet standards, set specifications and are fit for purpose.

Aesthetics are important when choosing new windows.

One of the critical considerations, when you choose new windows for your home, is how they look. Appearance is where all three materials can differ. The most significant advantage of aluminium windows compared to PVCu and timber is that they are usually much slimmer.  In contrast, there are also several brands of aluminium windows that are thicker in appearance. These thicker aluminium windows are intended to replicate traditional windows such as flush casement timber windows.

However, if you desire slimline windows first and foremost, aluminium is the winner.

In choosing aluminium windows your property style is another factor.  You may want to replicate your existing windows such as Crittall® windows, traditional timber windows or sliding sash windows.  For some window styles, some materials work better than others.  The good news is, PVCu, aluminium or timber windows mostly come in all the different opening styles.  Options include fixed, outward opening windows, tilt and turn windows and sliding windows.

Aesthetics are important in deciding what profile style you want from your windows.  Most casement windows come in flat, sculptured or ovolo styles.  For very flat modern windows, aluminium tends to be the preferred choice, although profiles sections are also available.

Where to use pvcu, aluminium or timber. 





Contemporary looking windows

Widely available

Few Options

Widely available

Steel or Crittall® replacement windows


Not Available

Not Available

Cottage windows


Widely Available

Widely Available

Sliding Sash Windows

Limited Options

Many options

Many options

Large picture or gable windows


Restricted by Size

Restricted by Size

Conservation Area Windows

Sometimes Approved

Often Approved

Frequently Approved

Windows with hardwood subframes


Not recommended

Not Applicable

Feature windows such as above bifolding doors


Not recommended


Flush Casement Windows


Widely Available

Widely Available

Frameless Windows


Not Available

Not Available

Hybrid Windows


Rarely Available


Oversize/Heavy Duty Windows


Not Recommended

Subject to sizes

As you can see, aluminium windows cover most window requirements but are generally not used for traditional windows such as sliding sash windows.  Similarly, aluminium, PVCu and timber products all have their distinct advantages. It all depends on what you want and your property.

By far the biggest advantage of aluminium is bigger windows and doors with slimmer sight lines.  PVCu and timber windows generally cannot meet the need for expansive glazing such as floor to ceiling windows.

steel style window

Colour choices for aluminium, PVCu and timber windows.

For all window materials, modern technology means a big colour choice.  Aluminium windows offer a bigger selection of colours thanks to the extensive RAL and other colour ranges.  PVCu windows also enjoy a great choice. Options include wet painted windows or using a foil.

Timber windows also give you colour choices.  You can colour-match to Farrow and Ball, Laura Ashley and other premier paint brands.  The same can also be done with aluminium but expect to pay extra for this and wait a long time for your windows.

When it comes to dual colour windows, aluminium and timber are easier to produce.  Different colours inside and out are also possible with PVCu windows. However, with PVCu you may end up with an unsightly joint where the two colours meet or bare profile on the unseen faces.  Aluminium and timber windows overcome this because of the production process involved. 

Aluminium is best for contemporary colours.  You have the choice of metallic, anodised and textured paint surfaces. Timber and PVCu don’t offer this option. 

Just like PVCu and timber, some aluminium systems such as Origin and Smarts Windows also come in a choice of woodgrains.  These specialist colour are applied to the aluminium profiles but expect less choice than with PVCu or timber.

Both PVCu and aluminium colour choices and methods of colouring should provide you with an extended guarantee.  However, when it comes to windows for swimming pools, coastal or exposed environments, aluminium is recommended over PVCu every time.  Timber windows chosen right can withstand more severe locations. Speak to an expert timber windows provider to understand if there are any restrictions or limitations.

Colour differences comparing PVCu with aluminium





Swimming pools and coastal locations.

Aluminium recommended with a dedicated marine warranty

Not recommended

Not recommended

Colour choices.

The biggest choice with nearly 200 to choose from

Typically 20-30 standard RAL colours

Extensive choice of colour

Colour matching to bespoke colours.

Available at a cost/special order

Generally not available

Available at a cost/special order

Colour matching door hardware

Available with most aluminium systems

Limited availability

Some availability

Woodgrain colours

Few systems offer wood-effect and lengthy lead times.

Renolit foils offer greater choice and shorter lead times

Natural stains and woods

Metallic and dual colours

Widely available

Not available

Not available in metallic

Aluminium, PVCu and Timber Window Security.

Much is made around the strength of aluminium as a material compared to PVCu and less so with timber.  It is true that aluminium is strong compared to its weight and slimline proportions. However, do not be misled that aluminium is somehow more secure than PVCu or timber windows.

Systems companies submit their products for security testing to meet one or more of the following standards:

  • PAS24
  • Secured By Design
  • Document Q for new build properties
  • European Standards such as WK2 or WK3

Our message around pvcu, aluminium or timber windows is that these windows are secure and are usually subjected to the same security tests, certification and methods of attack. Some websites will mislead you into thinking PVCu windows are weak therefore more susceptible to a break-in.  We say any window can be broken into if the burglar has enough time to do so.  The window industry is supported by security organisations such as Secured By Design and the British Standards Institute and Kitemarking to ensure you get the best security you can for your windows.

We recommend you ask to see the security certification applicable to the windows and make an informed choice. As a minimum, you can expect multi-point locking, secure and lockable window handles and additional security enhancements with most current-generation timber, aluminium and plastic windows.

U-Values and Window Energy ratings for timber, PVCu and aluminium windows.

All three window materials are designed to meet the minimum requirements of the current Building Regulations of 1.8Wm2K or a C WER (Window Energy Rating).  PVCu windows offer the best window energy ratings with double glazed units.  Timber and aluminium can give you similar but will typically need enhanced glass specification or triple glazing.  Therefore if the lowest U-Values and best Window Energy Ratings matter the most, PVCu windows are hard to beat.

However, in our experience, energy ratings are rarely the deciding factor when choosing new windows. Talk to your supplier, and they can work with you to ensure the best combination of frame and glass to meet your needs.

Maintenance Considerations with PVCu, aluminium or timber windows.

There are extensive and sometimes misleading sales messages around anticipated maintenance for aluminium, PVCu or timber windows.  Both aluminium and PVCu are rightly marketed as low maintenance but be aware; no window is absolutely maintenance free.  

For the surface finish especially, regular cleaning of both PVCu and aluminium frames ensures they keep their colour and appearance for longer.  Timber windows now have a lot of technology applied to their paint finishes making them virtually as durable and resistant as aluminium.

It is important to explain the role of the painted surface on aluminium and timber windows. Both the powder-coated surface on aluminium and the painted surface on timber windows is there to protect the material as well as provide your choice of colour.

If you damage the paint surface on either of these materials, it is likely that over time, both will deteriorate.  Yes, aluminium can corrode if the paint surface is damaged and moisture gets into the bare aluminium beneath.  This is no different to timber windows.  Should you damage the paint surface on any of these windows, it is advisable to get it repaired as soon as possible.

For PVCu the bare plastic profile is far less susceptible as it is merely a polyvinyl material.

Some locations may only require occasional cleaning; others will need more frequent schedules. Qualicoat offers comprehensive guidance on cleaning powder coated frames that you may want to read. 

For timber windows, we recommend you speak to a professional supplier that can give you the correct information on the guarantees, maintenance and care needed for the window surfaces. However, advanced micro-porous coatings and general paint technology come as standard with timber windows, and considered alongside PVCu and aluminium. 

residence 9 pvcu

Prices for aluminium, PVCu and timber windows.

PVCu windows are the cheapest of the three materials.  Aluminium sits between plastic and timber, with the timber window usually being the more expensive products.

The price you pay depends on some factors.

  • Your supplier being either an installer or a manufacturer or both.
  • The price point of the window brand and brand perception.
  • Company profit margins and installation charges.
  • Administration costs for giving you FENSA certification and your guarantee.
  • The colour and specification of your windows.
  • Extras and accessories. 

Always get two or three comparable quotations and ensure that the prices you quoted are on a like-for-like basis.  There is little point in assuming aluminium windows are prohibitive if you are comparing a standard PVCu window with a frameless, structurally bonded product.  If you’d like information on where to obtain prices for your windows, please get in touch with us.

Summary. Helping you make an informed choice.

The good news is, aluminium, PVCu or timber windows all provide attractive, energy efficient and secure windows for your home.  They also give you a choice of aesthetic and colour.

When to buy PVCu windows.

PVCu windows have also advanced significantly in recent years. You cannot dismiss their market dominance in UK home improvements.  The product is easy to make, very cheap to buy, gives the right margins to installers and is a reliable product.

If quality windows at the lowest possible price are your priority, then PVCu has to be a consideration.

When to buy timber windows.

The low-quality timber windows you will often find in new build developments where cost is the primary concern of the developer.  The high quality timber windows in the marketplace have had many of their problem areas designed out to result in windows which come with 20-year guarantees, long life of up to 50 years or more, high security, excellent thermal properties and high quality hardware. Timber windows are ideal in conservation areas where traditional aesthetics are so important. 

Strict regulatory controls address the sustainability argument for timber windows. Many timber windows today are manufactured from engineered softwood as well as general responsible sourcing of material.

When to buy aluminium windows.

Aluminium has been used in residential homes for many decades already.  You will rarely see PVCu windows installed in high-end homes, bespoke builds or properties designed with an architect.  All these projects demand aesthetics, qualities and performance where aluminium is the most suitable product.  

Aluminium has been used commercially for many years testament to the long-term performance of the product. You will very rarely see PVCu windows and doors installed in demanding environments such as schools, offices, hospitals or shops.

By nature of its inherent strength, aluminium windows and doors can be made wider, taller and more substantial than pvcu.  Opening vent sizes of 1600mm square are possible with some systems as are floor to ceiling or panoramic fixed windows.   

We summarise the advantages of aluminium, PVCu or timber windows:

Aluminium Advantage

PVCu Advantage

Timber Advantage

Ideal for high traffic and exposed environments

Cost effective

Warm, natural material.

Bigger range of products available.

Ideal for rental property or properties improved for resale

Very attractive windows and doors.

Bigger window sizes available

Great choice of foils and woodgrain colours

Will outlive PVCu and aluminium windows when looked after.

Substantially slimmer profiles and bigger glass areas.

Lowest window energy ratings.

Ideal for heritage buildings and conservation areas

Shapes are easier to create

Re-creates butt joints of timber windows.

Great for character homes.

Highly desirable modern products.

Better replicates the aesthetics of old timber windows.

Most types of windows available in timber

Perfect for replacing steel windows.



Substantially bigger choice of colours and colour options



Less thermal expansion means tighter tolerances and better sealing.



In considering aluminium, PVCu or timber windows, aesthetics still play the largest part.  The entire fenestration sector acknowledges that pvcu and timber windows will have thicker sight lines compared to aluminium. You will not find other materials with the slimline proportions of an aluminium window.

Contact us for further information, to answer any questions and to put you in touch with local providers of aluminium windows for your home.

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16:42 30 Oct 23
Nick responded incredibly quickly to my enquiry (on a Saturday too!), and was able to offer invaluable advice on both aluminum systems and manufacturer / suppliers. Thanks Nick!
chris steerchris steer
16:18 09 Oct 23
Had a meeting with Nick during the grand designs show. Was extremely helpful and professional would highly recommend
Chris WesthorpChris Westhorp
19:55 13 Sep 23
Extremely helpful with pointing us in the right direction to find the products we required and suggesting firms that could reliably fit them.Nick was quick to reply and very detailed in his advice.Highly recommend reaching out to them.
Cathy GreenwoodCathy Greenwood
07:03 11 Sep 23
Update - A second email to nick for help on bifolds resulted in a detailed informative reply even on a Sunday ! This guy is so knowledgable and helpful .I approached Nick for an independent view on sliding doors v bifold and the different brand options . His reply was extremely detailed and prompt and allowed me to navigate this often confusing world in a much more informed way . Thanks so much Nick
Anthony CraigAnthony Craig
12:45 05 Sep 23
This is a must site for anyone looking for advice. Great service and very quick answers to questions. Nick has been of great help quiding us through the maze of aluminium products. Thank you
Philip DuffieldPhilip Duffield
20:24 26 Jul 23
I contacted Nick @ ATS for guidance on what aluminium sliding door systems would be suitable for an opening in an extension that is going to be both wide and tall. He came back really quickly with very detailed and incredibly helpful advice. He is clearly extremely knowledgeable about the systems on the market and their respective features and capabilities. If you’re feeling a bit lost by the overwhelming range of choices out there, I’d definitely recommend contacting him.
Dariush HekmatDariush Hekmat
17:25 19 Jul 23
Nick's advice is great. He is always quick to respond and spends time on responses, which really help to make an informed decision.
Alan FosterAlan Foster
07:51 12 Jul 23
Absolutely fantastic. Asked for advice about replacing Crittall (?) windows late last night and early this morning received 3 great suggestions and contact information for suppliers
Rachel LauRachel Lau
09:24 16 Jun 23
Fantastic website full of valuable and pragmatic advice about product selection and comparison: no other website gives information like this. Truly written for public interest. Don't hesistate to reach out to Nick via the mailing system. He responds very quickly, is friendly, and has very sound and high knowledgable advice. I have already shared this with my friend planning her own grand design.
guard Charlieguard Charlie
12:28 14 May 23
I emailed this company just on the off chance they could help me with new magnetic sliders for my patio door. They were not able to supply those but were so very helpful providing me with the name of a company who could. I am so very grateful at the great service. Dare say customers must be very happy. thank you so much.
Benjamin LewisBenjamin Lewis
10:06 04 May 23
Nick is very helpful indeed. Extremely knowledgeable on bifolds which was in relation to my query. Great website as well, some very useful articles. Particularly appreciated the article that lists all the major bifold options in order of their sightlines! Thank you!
P JonesP Jones
08:07 15 Apr 23
I asked Nick some questions about an installation we were considering and he replied within hours with some very useful suggestions that will probably lead us to using a different make and supplier. Thanks, Nick. Great work.
Nicholas WallNicholas Wall
13:18 02 Apr 23
Looking for fair and honest expert advice on all aspect of aluminium windows and doors? These guys will arm you with all the information you need to make the RIGHT choice in a highly complex, crowded marketplace. post a question and you will get a very quick professional answer you can rely on being based on fact. Thanks guys!
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16:25 21 Mar 23
After a lot of research to find doors that would meet our unusual size requirements and feeling increasingly uncertain about the best way to spend our small budget, I stumbled on the ATS website, and I'm so glad I did! I contacted ATS to request advice and Nick promptly replied with a wealth of information, providing us with options and relevant contact details. I only wish I'd found them sooner!
Carol NortonCarol Norton
10:01 17 Mar 23
I've been so confused about how to achieve the look I'm after, and going round in circles with various window/door companies, trying to get away from the huge chunks of plastic currently around my windows. I didn't expect an email to a company found through a Google search to really help - but I was desperate, so I tried. I'm SO glad I did. Finally I have clear explanations from ATS of where I've been going wrong, exactly what I'm looking for, and a list of local companies that might be able to provide it! The response has excelled my expectations and I feel as if I'm finally inching closer to a home with which I'll be happy and comfortable: thank you.
David NunnDavid Nunn
20:54 14 Mar 23
It is rare that I write reviews, however after my very positive communication with Nick - enquiring about suitable slim sash aluminium windows for my project, I felt that a review was definitely warranted. I can reinforce the many positive reviews posted so far, Nick was very quick to respond, providing comprehensive detail, with excellent independent advice.In summary, great service, thank you Nick.
Chantal AuerbachChantal Auerbach
13:04 09 Mar 23
Nick from Aluminium Trade Supply was incredibly helpful informative and pleasant to deal with. He responded quickly to emails and was very knowledgeable. Highly recommend being in touch with Nick if you are considering new aluminium windows or doors.
Lee JonesLee Jones
20:21 22 Feb 23
I dropped Nick at Aluminium Trade Supply an email re high security slim sightline bi-folds and their alternatives and he responded that quickly (and so comprehensively) that I felt bad I’d not paid him for his time!Nick Sir your product knowledge is outstanding and you are providing a level of service that goes wayyyy above and beyond expectations. I’ll definitely make sure I mention Aluminium Trade Supply to anyone I encounter looking for a fenestration solution 🙏🏼
15:13 13 Feb 23
We are looking to replace some old UPVC patios doors with aluminium ones. The ATS website is a great source of advice in an area where clear information is sorely lacking. Having used the website, I then followed this up with a number of specific questions relating to our search, and Nick came back very quickly with clear, detailed and very useful advice.I have been very impressed with both the website and with Nick's advice. My only regret is that I didn't come across ATS before replacing various windows in 2021 - I'm sure it would have saved me a lot of grief and money! Thanks again Nick.
Azza McCabeAzza McCabe
17:47 01 Feb 23
So impressed with this company.Responded to my query quickly andgave valuable advice. Nick was extremely helpful and we were able to move forward with our project.
Adri LoloçiAdri Loloçi
11:21 08 Jan 23
Nick was super fast to respond and provided some great recommendations. I would recommend this website to anyone looking to find bifold or sliding aluminium doors.
Stephen HoustonStephen Houston
16:16 03 Jan 23
Looking for aluminium crittall style internal door and external patio French doors. Noted good reviews and thought would ask for advice. Comprehensive reply with excellent independent advice and lists of fitters who could provide products and installation. Great service.
Inga GeachInga Geach
08:25 21 Dec 22
Nick from Aluminium Trade Supply has been extremely helpful with navigating the jungle that is aluminium glazing for our upcoming extension project. His advice was prompt, detailed and always impartial. Very grateful for your input, thanks Nick!
Amanda BurtonAmanda Burton
10:54 16 Dec 22
Brilliant website and an excellent service. Nick provided not only detailed advice and supplier contacts, but highlighted the considerations of various products so I could make an informed choice. Our Sunvista minimal sliders were fitted this week and I couldn't be happier, stunning. Thanks once again for your advice and recommendations, invaluable!
Keith BarnesKeith Barnes
17:18 10 Dec 22
Very helpful advice given to my question, including the name of 3 different companies that i could try for the product being enquired about. Many thanks
Munim ChowdhuryMunim Chowdhury
11:45 13 Sep 22
Nick has been very helpful on signposting me to a number of partner organisations for steel/aluminium doors.
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17:26 31 Aug 22
My experience with this firm was exceptionally good and this is notalways the case as a female, dipping a toe into technical waters.I was spoken too with courtesy and at a level that helped me consolidate what was needed .On top of that I was given a list of companies and places where I could obtain the type of product I needed.I could not thank them enough and would certainly go there again and reccommend others do too.
Paul SalterPaul Salter
22:39 22 Aug 22
Contacting Aluminium Trade Supply is like contacting the Oracle direct. Advice is always comprehensive and balanced. On multiple occasions they have provided me with options that fully meet our objectives. Many thanks.
Nick McCormackNick McCormack
20:25 14 Aug 22
Really helpful and useful came back to me on a Sunday with some invaluable information. Highly recommended.
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13:14 14 Aug 22
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