Who makes the best aluminium windows?

When it comes to windows and glazing for residential properties, and you want to find the best aluminium windows to replace dated windows or for a new extension or new build, this article tells you all the essential things you need to know.

We will also delve into the practical aspects of design and options, security, energy efficiency, and colours. These tips are designed to make your search for the best aluminium windows easier, especially when you need French, bifolding, or sliding doors to match.

The best aluminium windows depend very much on their intended use, the style you want, and, in many cases, the brand. If you would like personal help and advice, please get in touch with your specific questions.

How to choose the best aluminium windows.

Based on the opening type and the look you want to achieve, here are the best aluminium windows by category:

Best casement slimline windows

Looking for the slimmest possible windows? New build openings typically allow you to have narrower frames. You’ll find window replacements call for a slightly thicker front-to-back or frame width dimensions, but the most suitable replacement window very much depends on the survey.

Reynaers Slimline 68

One of the better aluminium windows brands, Reynaers Slimline 68 delivers contemporary sightless, infinite design options and thin frame and opening sash profiles. With sightlines of between 15mm and 65mm depending on the configuration, Reynaers SL68 promise beautiful styling, gorgeous window handles and the legendary Reynaers engineering and quality.

Schüco AWS 70 SC

A premium window brand Schüco markets their windows as barrier-free, with good reason. Schüco AWS 70 SC is developed specifically for the UK market and comes as fixed or outward opening versions. The sightlines are slim at around 38mm for the outer frame and 51mm for the opening vent profile. These windows are superbly well-designed, built with the incredible Schüco quality and come recommended. Even better with Schüco AWS 70 SC is their impressive size capability, opening vents can go up to 1.8m wide or 1.8m high.

Smart Systems Alitherm 400

Alitherm 400 is very stylish, and affordable and comes with a matching range of residential side and back doors. Available double or triple-glazed, Alitherm 400 comes with side or top opening windows at impressive sizes, meaning bigger panes of glass and fewer mullions and transoms. It’s, therefore, very good for contemporary windows in new extensions or new-build homes. With substantial frame options, Alitherm 400 creates windows in several frame styles and has very pleasing slim sightlines of 59mm with a fixed module and 71mm with an opening vent.

Origin OW-70

Expertly made by Origin, their slimline OW-70 aluminium windows promise slim sightlines, high quality hardware and a dependable manufacturer guarantee. These, too, come with a 65mm sightline but don’t come in every possible configuration, for example, bay windows. However, they’re widely available, meaning prices stay competitive. The exterior flush casement design is also very pretty compared with the overlapping nature of window vents on other systems. The OW-80 by Origin is even better in terms of performance but quite a bit thicker.

aïr MOD series windows

The downside to aïr MOD windows is that they’re only available south of Birmingham, however, these are an independent system, available in five different versions, and the styling is outstanding. Available as a flush casement, contemporary window, slim steel-look and a tilt and turn, all of these windows come with very pleasing styling, fantastic quality and made by one of the longest established aluminium manufacturers in the UK.

Best floor to ceiling windows

Choosing a well-designed system with floor-to-ceiling windows is limited only by the capabilities and maximum sizes of the glass and the competence of the window company. Essentially any current aluminium window will work as a fixed floor-to-ceiling window. Therefore, there isn’t an overall best system, but there are products designed to create the best possible floor to ceiling glazing and glass walls.

Reynaers Masterline 8

The top end window system by Reynaers, Masterline 8 stands out for its gorgeous frame styling and impressive capability. Masterline 8 also combines doors and windows but is styled in such as way that any floor to ceiling window looks ultra-modern, sleek, elegant and also timeless. Options include glass corners and opening elements if required.

Schüco AWS PD.SI

Schüco is renowned for the engineering and design of its systems and the PD, or Panorama Design, is no exception. Better suited to contemporary new builds, Panorama Design comes as floor to ceiling windows that can be fixed, have a hidden opening system and even a fully opening element for ventilation. Schüco AWS PD.SI promises minimal framing and excellent thermal insulation. It’s the kind of system you see in ultra-modern Grand Designs houses created with glass walls in every room.

Cortizo Cor-70

A more affordable option, Cortizo COR-70 has pleasing European styling and looks great as a fixed window capable of large widths and heights. This system also comes as a hidden vent option allowing for slimmer windows but also opening for ventilation, without the bulk of traditional casements.

Best tilt and turn aluminium windows

tilt and turn window

Tilt and Turn windows aren’t as popular in the UK as they should be, but they’re better than casement windows in several ways. First of all, the size capability of tilt and turn windows is significantly better than side or top-hung outward-opening windows. With heights up to the size of a standard door, tilt and turn windows are great for flat roof terraces or when you simply want bigger opening windows.

Their main function is tilting inwards for ventilation. Then you can rotate the handle in the opposite direction, and the entire opening element swings inwards. Not everyone likes the idea of an opening inwards window, however, they also have the advantage of letting you clean the outside pane of glass from inside the room.

Once again, Schüco arguably makes the best tilt-and-turn window because theirs has passed security testing in the open tilt position. In contrast, every other window is tested in the fully closed and locked position! Smart Systems, Aluk and Reynaers and aïr MOD also make excellent tilt and turn windows worthy of consideration.

Hybrid windows use aluminium outside and real wood inside. These have been available as tilt and turn for many years already and, in our view, are also some of the best, not to mention the warm-to-the-touch inside of real wood and its timeless style. You can get in touch with us for more information on hybrid windows or doors.

Best flush casement aluminium windows

The flush casement or timber-look window is relatively new in aluminium. However, the flush design where the opening vents are flush with the mullions or frame has been around for longer with plastic windows and also hybrid materials.

Origin OW-80

Origin’s OW-80 window is our top choice for the best flush casement aluminium window. The styling is excellent, also being unique in having a flush look on the inside too. It’s well-priced, widely available and has features top-brand hardware and excellent insulation when upgraded with Aerogel.

aïr MOD flush casement

We love the flush casement version of the aïr MOD range of windows because it’s so flexible and easy to integrate with the four other styles available in the collection, whether casement, steel-look, contemporary or tilt and turn. It’s not available everywhere, but worthy of consideration. The styling is really good too as are the slim overall sightlines for a tilt and turn, that’s usually bulkier in other systems.

Smart Systems Alitherm 500

Another excellent flush casement aluminium window, Alitherm 500 comes as fixed or opening windows, including large openers and a top or side-hung opening design. You can use this window in dwellings or light commercial projects. The window has reasonable U-Values depending on the glass used and the typical 65mm sightline also makes them much slimmer than the Origin version. Another great styling feature of the Alitherm 500 is the integrated trickle vent section, essential in all new windows now, and a very smart cill section that looks streamlined with the window.

Best aluminium sliding sash window

Unfortunately, aluminium still has quite a way to go in providing pleasing vertical sliding sash windows. Right now PVCu systems do it much better with Roseview, Masterframe and others providing authentic styling. However, if you must go for aluminium there are two excellent choices available.

Duration Royale

The Royale sash window made by Duration Windows is beautifully slim and has some of the thinnest meeting rails, typical of old timber windows at only 42mm.

This window has an excellent mix of traditional features with a chamfered sash, a choice of cills and side sections and frame depths that make installation easy. As well as the traditional sash horns, Duration Royale comes with period hardware if required, highly insulated glass units and a tilt in facility for the sliding sashes, letting you clean the glass from the outside.

aluminium sliding sash windows in a showroom

Smart Systems VS 600

Suitable for dwellings or commercial buildings, Smart Systems Alitherm 600 looks really good in modern houses designed in the period style and provides a slimline sliding window, also available with optional sash horns. VS 600 is also widely used in non-dwellings where a school, care home, hotel or hospital would prefer the inline opening without opening windows projecting outwards.

The aluminium window common features

Helping you understand aluminium windows, it’s first of all worth explaining the three common features of most aluminium windows. Importantly, whichever brand you go with, certain aspects of your new windows are the same. This then leaves you to choose the right product based on brand, styling or a specific design or functional requirement. These common features apply to both replacement windows and those for a newly built opening.

An explanation of the glass in aluminium windows

Similar to thermal insulation, meeting the required energy efficiency stipulated by Building Regulations also applies to your glass. Single glass does not meet these requirements. Therefore, you won’t find anyone selling single glazed exterior windows.

All of the best aluminium windows, including mid-range and trade windows, come with double glass units as standard. Most windows are designed for 28mm thick although 24mm is also acceptable.

Again as standard, expect to get a minimum glass specification of a soft-coat low-emissivity (low-e) coating, warm edge spacer bars and argon gas fill.  The low-e coating helps retain interior heat, the spacer bars are the edges of your glass and the argon gas instead of air creates a high performance glass in your windows.

How aluminium windows are coloured

Finally is the painted surface of your new aluminium windows. This advanced powder coated finish not only provides colour. It also protects the bare metal surface.

Your new windows come painted by specialist colour applicators under strictly controlled environments. Again, most products you see come with a surface finish of similar quality.

pvcu thermal break in a window
A typical thermal break in an aluminium window profile helping with energy efficiency

Understanding what thermal insulation in windows means

Also known as thermally broken, energy-efficient or insulated, all exterior use aluminium windows come with thermal insulation. In simple terms, the aluminium profiles are separated by a non-metal component (the thermal break) between the inside and outside faces of the window profile. Its job is to prevent the transfer of cold.

It’s this thermal insulation combined with the double or triple glazing giving you windows with good window energy ratings or U-Values but also windows that must meet current Building Regulations for energy efficiency. All windows meet these Building Regulations as well as safety, ventilation and means of escape such as in a fire. It’s highly unlikely you’ll find any aluminium window today without a thermal break.

Standards and specifications for aluminium windows

Further illustrating similar technical standards of aluminium windows, the following table shows window specifications and standards you’ll find most comply with.

For the critical components of windows like the profiles and the paint finish some systems companies produce in-house. Other systems companies outsource to independent extruders as well as specialist powder coaters. Specialist manufacturers produce rubbers and seals.  Your glass comes from glass manufacturers. Therefore, when it comes to the quality of everything that makes a window, you can regard quality as generally the same.

Again this leaves you to focus on style, design and personalisation options.

FeatureRelevant Industry Standard
Quality of aluminium profiles and extrusions Aluminium Alloy 6063.T6 to BS EN 755 Part 9: 2008 or BS EN 12020
Quality of polyester powder coated finishBS EN 12206-1:2004.
Quality of glassBS 6262 and Approved Document N
Quality of glassBS 6262 and Approved Document N
SecurityPAS 24, Document Q, Secured by Design, BS7950, BS EN 12209
Weather resistanceBS 6375: Part 1, Part 2 & Part 3:2009
Water resistanceBS 6375: Part 1, Part 2 & Part 3:2009
Air permeabilityBS 6375: Part 1, Part 2 & Part 3:2009
Quality of rubber gasketsEPDM Rubber manufactured in accordance with BS3734.
Quality of woolpile sealsBS 7386:1997
Polyamide Thermal BreakPA66 GF25
Anodised coloursSilver or bronze anodised BS3987 (AA25).
Aluminium window standards and specifications

Who makes your new aluminium windows?

The vast majority of window installers do not make any windows. Instead, they buy them from specialist trade manufacturers. Some of these trade manufacturers work incredibly closely with their customers (your installer), with product training, installation support, pricing software and marketing.

Many installers are rightly proud of their relationships with the factories making your new windows and you can ask them to reveal either the supplier or the system.

There’s now the option for you to buy your new windows direct from some manufacturers and getting your builder to fit them. The obvious benefit is saving money although it’s unlikely you’ll get the same guarantee and support you would with the full supply and installation service.

Understanding your window ‘system’

The window system is the brand, the aluminium profiles and accessories. Also within the system is bringing the window to market, testing for security or weather performance. Aluminium windows systems companies invest substantial sums designing some of the best aluminium windows.

Then, the system including aluminium profiles, accessories and components are supplied by the systems company to its network of manufacturers. At the same time, these manufacturers are trained and supported by the systems company ongoing.

Your relationship is with your supplier and installer. They work with their manufacturer and supplier who in turn works with the systems company.

There are some exceptions to this with some systems companies also making their own windows also acting as suppliers. Origin is one of the best known brands of windows as well as sliding and folding doors working in this way. Anglian and Everest, two of the biggest names aren’t systems companies by they make their windows buying profiles from a systems company.

What does this mean for you? Often these systems companies come with decades of aluminium experience and frequently part of global groups. Schuco and Reynaers is an excellent example of two systems companies providing some of the best aluminium windows available, made through their network of manufacturers.

The aluminium window brands.

The following window brands, including specific variants, you can consider as some of the best aluminium windows. The reason they’re the best is down to several factors including who makes them, the overall design and quality, styling options as well as brand reputation. This is also reflected in the pricing.

Mid-Range Aluminium WindowsBest Aluminium Windows
Stellar Aluminium WindowsSchuco Windows
Aluk Optio 58BW casementReynaers Windows
SAPA Crown Casement WindowSmart Systems Heritage Range
Comar Eco and EcoLT windowsSmart Systems Alitherm
Sheerline Classic and PrestigeOrigin OW70 and OW80
Everest Aluminium Windowsaïr MOD aluminium windows
Anglian Aluminium WindowsKeller Minimal Windows
Senior Architectural Windows Windows from IQ Glass
Kaye Building Systems KBSWindows from Panoramah
Deceuninck Decalu Windows AluK Optio 58BW ST steel replacement
Cortizo Aluminium Windows
Table of mid-range and best aluminium windows

The reason Reynaers and Schuco are widely regarded as the best aluminium windows brands is the multiple window solutions and different window products they design.

As well as this, Reynaers and Schuco have a portfolio of windows that are specialist and intended for specific requirements and uses. Examples include fire-proof, bomb and blast-resistant windows as well as maximum security windows for buildings where security or protection is critical.

It’s this expertise and window knowledge passed onto their windows and doors for dwellings making them some of the best aluminium windows available and the choice of leading architects and designers.

Of course, other specialist window businesses are creating high-end architectural glazing. Still, these are for Grand Designs type projects, often different from the windows and doors most people want for their home or new extension. Examples include windows disappearing into the floor, floor to ceiling windows, guillotine windows, frameless box windows and many bespoke window creations.

Why the best aluminium windows differ

steel style window

How to identify a good window from a bad

The good news is there are no ‘bad’ aluminium windows. Most brands share similar material specifications, quality and production standards or security specifications and more. It is incorrect manufacturing or installation creating a bad product and customer experience. It’s rarely a design fault with the window system itself.

Aluminium systems companies invest substantial sums in testing, certifying and bringing their windows to market, even those at the mid-range or trade price. Consequently, window problems come lower down the supply chain.

Some installers dislike certain brands as they find them complicated to fit. This is however of little concern to the homeowner customer. Or reports of leaking windows or those letting in drafts are again down to incorrect manufacturing or installation.

Security of aluminium windows.

stellar black aluminium windows

As we mention, many of the best aluminium windows share standardised specifications.  Some windows come with enhanced security, others with more basic.  Therefore you can take it as granted that all major systems are independently security tested.  Ask to see the certification and check the credentials of the tested window.

The locks, handles and hardware found in aluminium windows.

The multi-point locks, window handles and components used to make your aluminium windows come from global or British companies that specialise in designing and producing hardware for windows and doors. The same applies to the seals, gaskets and rubbers.

Some aluminium systems use standard locks and handles. Other systems companies may work with more high-end lock companies such as Yale, Roto or Winkhaus, widely regarded as providing better locking systems.

It’s the window hardware where Reynaers and Schuco mentioned earlier that stand out. Schuco for instance provides automation with their window handles. Reynaers offers designer hardware even with anti-bacterial and high-end finishes and textures.

Why your windows don’t need to match your doors

The functionality of a window and a door are entirely different. It’s for this reason they don’t match. Therefore there’s no specific reason why the best aluminium windows from one brand need to have matching doors.

For example whilst Reynaers and Schuco design better aluminium windows, a customer may want a minimalist and super-slim sliding door – something not available with either of these brands. Similarly, Origin makes excellent slim or traditional looking windows but you can’t find a slide and stack bifold door in their range.

Therefore, it’s not a problem having windows from one system, your grand patio doors from another and even a front door from an alternative brand. It’s about choosing the right product for your property project.

There are just a few advantages to having windows and doors all from one brand:

  • A single point of guarantee instead of two or three
  • You like the idea of a consistent brand in your home
  • Your choice of brand or system meets your project needs
  • Often one brand saves money overall

Our top tips for choosing the best aluminium windows

  1. It does not matter if your doors and windows are different brands. Consider allocating more of your budget to premium doors and less to the windows.
  2. Ensure the information provided is factual. There is no ‘bad’ window on the market. Many share specifications and product standards.
  3. It makes sense to have combination windows mixed with doors from the same system. But not essential.
  4. Consider either opening options. Examples include sliding, reversible, opening in, pivoting, tilting and automatic windows.
  5. Beware the many re-brands of existing systems giving you the impression of being unique or exclusive.
  6. If you are buying different brands, here’s how to check your colours will match. 
  7. View your chosen windows in a showroom or exhibition. It’s the best way of understanding their make-up, styling and operation.
  8. Remember there is an aluminium window solution for most projects. Contact us for advice or where to buy.