Advice on buying steel-look windows

Buying steel-look windows in aluminium for homeowners or the trade is now better than ever. Thanks to product innovation, several brands and systems on offer and flexible design solutions, there’s never been such a choice. In this article, we explain more about the various products, designs and systems, for aluminium steel-look windows.

What are Crittall® style and steel-look windows?

Steel look or Crittall® style windows are typically slim multi-panel windows used originally in Art-Deco buildings or other property with original metal windows. These frequently come in black, feature a grid-like pattern and today are also known as industrial, Scandi, Heritage or period windows.

The original and existing product by Crittall® is the 100% genuine article. It costs more but only the steel version is exact for style, sightlines and quality. Aluminium versions take design clues from this authentic product. They’re not the same but create the same pattern and style in a more affordable material.

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Steel look windows and doors

The genuine steel window is slimmer than aluminium. It has a welded construction where aluminium has mechanical joints at the corners. The lifespan of steel is significantly longer than aluminium as well, although both materials are well known for being reliable.

Are steel look windows a fad?

There’s no doubt a lot of property suits this style of glazing, but it’s also true right now they are a design trend and incredibly popular. Whether they remain a fad remains to be seen, but steel-look and Crittall® style windows do work with modern home extensions, interior design and the ever-popular industrial and contemporary look.

We’ve seen trends come and go. Just over ten years ago bifolding doors were probably the most desirable. In recent years the trend has also shifted to slimline sliding doors too. Steel look glazing provides another style option for windows and patio doors.

steel-look windows in a new home made by everglade windows trade

Of course, in warehouse conversions into dwellings, barns, Art-Deco houses or new builds, this style of windows works incredibly well.

Are there any disadvantages to buying steel-look windows?

The only consideration with these products is being aware of the horizontal and vertical bars. Obviously, any multi-panel design creates a busier looking window or door and your views to the patio or garden are obscured by the bars. However, the popularity of this design is such that it’s a small compromise for the styling and appeal of these types of windows and doors.

What to know when buying steel-look windows

It’s important to first know the difference between steel-look and steel-replacement windows. Steel replacement is frequently a term used for windows intended to replace existing steel windows. The term steel-look refers more to the style of the windows, although these too are suitable as a replacement for existing metal windows.

There are a substantial number of steel window suppliers in the UK. Some of these make and supply the trade directly. Others provide windows via a network of approved dealers or retailers. There are also manufacturers making windows for their own installations.

As with any quality product, expertise is key. The popularity of these products understandably brings new players to the market. Some of these are credible options when buying steel look windows.

Others remain the standard window with applied bars giving the multiple panel effect. Whether these standard windows are steel-look is subjective. If the end-user is happy with the windows they’ve purchased, arguably they are. Alternatively, the more research-savvy buyer will probably want a more detail-orientated product where the design of the system takes inspiration from original steel windows.

Despite, the popularity of this style of glazing, some of the UK’s best and longest established fabricators have been making these products long before they were popular.

buying steel look windows showing crittall style windows in a loft apartment

Design and performance considerations when buying steel-look windows

Generally speaking, the steel-styled glazing available today has as its core current technology. Specifically, aluminium profiles, weather sealing, locking systems, the powder-coated finish and glass all meet industry standards for quality, conformity and type.

You’ll find these windows double or triple glazed, available in a huge choice of colours and virtually unlimited styles and shapes.

Energy efficiency is also very good with nearly all products, also meeting at least the minimum requirements of the Building Regulations for either U-Values or Window Energy Ratings.

For window security, each system should state what security tests the windows come with. Where a window comes with period furniture, for instance monkey-tail handles or peg stays, check whether the security certification (PAS24 or Secured by Design) covers the window fitted with this type of hardware.

The marketing messages around security can confuse. A reputable installer should give you clear information. And just because the system comes tested to the latest standards, doesn’t meet every configuration and window design will too.

Steel-look glazing bars on windows

It’s the glazing bars that play a big role in the overall look when buying steel-look windows. On the genuine steel product the glazing bars tend to be around 28mm such as the Innervision sliding door. For the steel windows, these come with 19mm, 26mm or 30mm bars.

Therefore, aluminium windows can also offer these bar dimensions or come close to them depending on the supplier and the product.

Some of the best brands when buying steel-look windows

The following brands come with a dedicated steel-look or steel-replacement system. Moreover, these are arguably some of the most credible on the market today in aluminium.

Smart Systems Alitherm

steel look doors in large screens

The earliest and most popular of the current aluminium systems in the steel-look, Smart Systems Alitherm Heritage have cemented their reputation as the best known windows, from the UK’s biggest aluminium systems company.

Whether it’s a standard system as intended, or customised with new/improved extrusions or rebranded, Alitherm is hugely popular when buying steel-look windows.  Also known as Heritage 47, the range of windows from Smarts comprises fixed and opening casements, tilt and turn windows, W20 steel-inspired designs as well as matching single and double doors. Many of the leading aluminium manufacturers set up for trade supply provide the Smart Systems range. Smart systems provide standard and heavy-duty versions, doors, and a new Aluspace interior system.

We even know of situations where the Alitherm 600 window has been used for internal New York-style screens. Even the Visofold 6000 bifold comes with a steel-styled sash profile. Image shows Alitherm windows fitted by Aspire Bifolds of Surrey.

It’s important to remember when buying steel-look windows by independent brands, that a number use Smart Systems either redesigned or standard products under a different name. This does not matter. It’s the quality of the product, installation and overall buying experience that matters the most.

aïr MOD Windows

air mod steel look windows

Made by Everglade Windows, air MOD come as some of the most diverse in type and style. 

With the air MOD product, you’ll find heritage, steel-look or art-deco windows with the option of some excellent period hardware and accessories. This brand of windows also comes as contemporary, flush and tilt and turn versions. They’re slim attractive and well worth checking out. Everglade is also one of the earliest manufacturers of steel-look products starting with the Smart Systems Alitherm and Alitherm 47 systems.  

air MOD is available to the trade and homeowners via an authorised and approved dealer network

Steel-look and Royale by Duration Windows

buying steel-look windows

Suppliers to the trade, Duration Windows make Aluk and Smart Systems products as well as a full range of aluminium doors and windows. 

The Royale Window is one of the slimmest on the market and comes with some excellent accessories and great attention to detail.  There’s also an interior sliding door version.

Four different versions are available. The Royale Stepped with impressive 33mm sightlines, a Putty Line appearance, Heritage Stepped and Heritage Putty Line. Buying steel-look windows from Duration is largely for installers and the trade but get in touch for details of installers providing these slim and well-made products.

Aluco Aluminium

buying steel-look windows

Steel-look windows by Aluco aluminium are available to homeowners via a nationwide dealer network. 

The range includes a comprehensive selection of casement and fixed windows as well as combination screens with doors. Using the Alitherm system, Aluco products suit general steel window replacements, stone or timber surrounds as well as new window openings. 

There’s also a range of doors, bifolding doors, internal screens and partitions and interior doors in the steel-look. When buying steel-look windows, the Aluco brand is very well known with excellent build quality and brand reputation. Their interior steel-look doors are also some of the best on the market today and also come as steel styled sliding doors.

Aluk Optio 58BW steel-replacement

steel style window

The Optio 58BW product by Aluk is widely used in residential and commercial projects offering a 58mm or 70mm frame depth, excellent security, energy efficiency and acoustics.

While not as popular as the Alitherm System, you nevertheless get a good range of options including flush casements, contemporary and heritage styles. 

Another good feature you’ll find buying steel-look windows by Aluk is the option for bottom hung opening inwards windows. 

Exlabesa KS59 Windows

Exlabesa KS59 windows joins the growing family of steel-styled casement windows. This product features the stepped edge detail of classic steel windows such as Crittall® with a similar design.

Exlabesa KS59 come as fixed or opening windows, deep 32mm thermal breaks and with PAS24:2012 security certification. Beating other steel-look windows sizes go up to 1200mm wide and 1500mm high on a top-hung design and 600mm x 1500mm on a side hung version.

Reynaers SL38

reynaers masterline windows in the steel look

Also known as the Slimline 38, Reynaerswindows deserve more recognition as a steel-look brand.

They come in Classic, Cubic and Ferro models all with highly attractive detailing, and the renowned Reynears design, engineering and quality. 

They’re a great alternative to better known brands of steel-inspired windows in aluminium and another option that’s worth checking out. Having seen versions of these windows, the Reynaers product is excellent, but you may also find it hard to source. Get in touch for more information on buying steel-look windows in the Reynaers system.

Jennyfields Windows

buying steel-look windows made by jennyfields
Image courtesy of

Whilst not a systems company or large fabricator, Jennyfields based in Surrey specialises in steel-replacement windows and specially expert in curved sunshine bays. 

Where you’ll find many installers shying away from these curved on plan bay windows, Jennyfields have been doing these long before the current trend for these windows. The company also replaces existing W20 windows with a warmer, thermally insulated version.

Brands and Systems not designed as steel-look windows

The following popular brands presently don’t have a dedicated steel look system, although they can be marketed as such. By dedicated we mean a window product designed from the ground up with specific steel-inspired profiles, hardware and characteristics for steel window replacements.

  • Origin OW-70 and OW-80
  • Stellar aluminium windows
  • Sheerline windows
  • SAPA Crown Windows (now under the Technal brand)

This is by no means a criticism of the above brands and we know of many situations where they’ve been sold with applied bars giving a steel look appearance. If you’ve seen these windows and like them, go ahead and buy them.

Window handles and accessories when buying steel-look windows

Furthermore, there’s an extensive choice of window accessories when buying these steel-inspired windows. With any good providers, expect to get a choice of different shapes, colours and textures.

Also important is the glazing bar styling and size. Again, a good system provides a range of options.

Replacing existing steel windows with aluminium

While a steel window remains the genuine and best type of window in this style, aluminium provides a cheaper and alternative solution. Be aware you will never get a 100% match for new or existing steel windows. Whilst we are an aluminium website and as good as these brands in aluminium may be, steel-remains the best looking and with exemplary quality and build.

Aluminium, therefore, provides a suitable alternative for the replacement of existing steel windows. However, and as you can see from these two images of a curved window, the inner radius curve is too tight to recreate in aluminium.

Crucially, take a look at the outer frame sightlines. There’s little to distinguish the slimline original window and the aluminium replacement using the Royale Product by Duration Windows. Installation carried out by Open Living of Letchworth.

Buying steel-look windows with shapes and curves.

Importantly, with some existing steel windows and doors features curved heads and other shapes, how does aluminium stack up?

First of all, whether you can recreate complex shapes depends on the tightness of the radius. Steel windows generally lend themselves significantly better when creating special shapes. This is especially the case for Gothic styles and curved on plan windows.

The main reasons why it’s difficult in aluminium for complex designs, curves or shapes is how the joints come together, the aluminium beads holding the glass as well as hardware considerations. As a result, opening window elements usually come square or rectangular only.

Here’s a gallery of window styles where generally you’ll struggle to get these in aluminium, but frequently possible on special order in steel.

The popularity of steel-look windows is set to get even better and aluminium systems and providers, continue to innovate and provide some standout products.