Double Glazed Aluminium Windows
As one of the longest serving double glazed window products, double glazed aluminium windows are enjoying a well-deserved popularity boost.
Although double glazing in the UK has been around in some form since the 1950’s, it was really the 1980’s where aluminium windows built their presence in the market via companies such as Everest and Anglian with secondary double glazing.
Over the years things have moved on a lot, with new or replacement aluminium windows now offering an excellent combination of design choice, energy efficiency, lifespan, low maintenance and security.
If you are looking to replace your existing windows in the near future, and to give you some help in deciding if they are right for you, this article is going to look at the main features and benefits of buying aluminium double glazed windows.
The top 5 things you need to know about aluminium windows for your home.
Not every home has the same look, and this is reflected on the choice of designs for aluminium windows which are now available:
- Casement: These windows open outwards on hinges from either the side, top or bottom. Arguably the most often used window design in the UK. Casement windows are seen everywhere in every style of property, from a country cottage to an ultra-modern “designer pad”. Top opening and bottom opening casement windows are sometimes called awning windows and hopper windows respectively.
- Sash: A favourite style to use in older style properties. Many pre-second world war and period homes in the UK (those built in Edwardian or Victorian times) feature sash windows. The opening function of this design is to slide up and down within the frame. Horizontal sliding sash windows are an alternative option. The typical configuration is to have 2 sections, top & bottom within a single outer frame. Single hung sash windows only open from the top section, double hung sash windows allow both sections to open.
- French: French windows are effectively a stylized casement design. The classic look is a side-by-side pair of side opening casements set within a single outer frame. The frame can be fitted with or without a centre mullion (post).
- Tilt & Turn: Yet another variation of the casement style, but in this instance the casement can be opened in two different ways. First is like a regular side hinged window, although it opens inwards. Second is by means of tilting the opening section. The window is able to “lean backwards” into the room which allows a lot of ventilation without having to open the window fully. The tilting or opening action is controlled by moving the handle in different directions to unlock each function.
Staying with visual design, the use of aluminium in the frames has another benefit. Because it is a metal and has great structural strength, it allows for thinner frames to be used. This has the effect of “streamlining” the window designs so that they look much neater and slimmer. It can also allow for wider spans and is therefore perfect to use in the case of something like a big “picture window”.
Aluminium is used widely used for its’ good conductivity properties, which for a double glazed window could be a problem. However, this potential drawback has been addressed by engineering a thermal break into the frame design.
The outer frame is separated from the inner frame by a polyamide break, thus isolating and insulating each side from the other. This thermal break stops the transfer of both heat & cold from one side of the window frame to the other.
The break has a neat side-effect; in that it also allows for the use of a different material for the inner frame. This has given rise to windows with aluminium outer frames and UPVC inner frames.
The frame profiles themselves are multi-chambered. This chambering not only reduces flexing, but also traps air inside the frames which acts as an extra insulating factor.
Another option is to use aluminium clad timber windows. These window designs are made from engineered timber frames that are fitted with an aluminium outer skin. This gives you a window with timber inside, timber & aluminium outside.
The double glazing unit itself is also an important element of the overall energy efficiency for aluminium windows.
You are likely to find either 18mm or 20mm sealed glass units fitted in a standard window. That means you have 2 x 4mm thick panes of glass separated by either a 10mm or 12mm gap. The highest energy rated windows are A++ and will be using a 20mm gap with an overall thickness of 28mm.
Double Glazed Sealed Unit Dimensions
In the gap between the panes you can substitute air for an inert gas such as Argon, Krypton or Xenon. Argon has only about 60% of the heat transfer properties of air and Krypton about 50% of Argon. However, you will find gas filled units, especially Xenon, more expensive.
3Colour and Texture.
One of the bonuses of using aluminium windows is the absolutely huge range of colour choice. Some manufacturers and suppliers have over 200 RAL powder coat combinations in their catalogue. If you combine that number with textured timber grain effect finishes, and the fact that you can have one colour inside and another colour outside, the result is an almost limitless choice for coloured aluminium windows.
The most popular type of finish is to powder coat the frames with a paint. This is done by applying the colour in powder form (hence the name powder coat). The coat is electrically charged to stick to the aluminium and then heat treated & cured to chemically bond it to the surface, giving a super hard wearing, non-fading result. http://www.powdercoating.org/page/WhatIsPC
4Security & safety
Having great looking windows is one thing, but if they are not secure then they are a waste of money. Modern double glazed aluminium windows have a number of security features.
Firstly, the use of 2 panes of glass, cushioned by a layer of gas or air, makes them far more difficult to break than a single pane of glass. Even if just one of those panes is toughened, it makes it yet more difficult to break. If a determined and forceful attack is to succeed, it will require making a lot of noise, yet another deterrent to burglars.
The glazing is fitted from the inside as standard, thereby preventing removal from the outside. Being made of metal, the window beads themselves are naturally tougher than timber or uPVC.
The aluminium frames themselves are also much more resistant to attack than both timber or uPVC.
Window handles are fitted with locks, and engage at multiple points around the frame. This multi-point locking ensures that once closed and locked, the windows stay closed and locked.
5Aluminium Windows Prices.
How much do aluminium windows cost?
Aluminium windows are not what you would buy if you want cheap double glazing.
Because the manufacturing process is more complex, prices for double glazed aluminium windows are usually higher than those of UPVC and softwoods. However, they do compare favorably with prices for hardwood windows.
For example, an aluminium tilt & turn window 1200 x 900mm costs around £500 supply only, and from £650 fitted. An aluminium casement window 750 x 900mm costs around £220 supply only, and from £350 fitted.
How much does it cost to fit aluminium windows to the whole house?
Many folks change their front and back doors at the same time as they change their replacement windows. So, to give you a rough guide, a good quality aluminium exterior front or back door can cost around £1,100 to £1,500 fully fitted.
In our humble opinion, double glazed aluminium windows represent the top of the range when it comes to looks, lifespan, ease of care, energy saving and keeping your family safe.
Admittedly, they are not the cheapest double glazed windows in the market, but you do get an awful lot of features and benefits for your money.
Using a guide to prices like this one is only going to give you a very rough idea of the likely costs involved in buying replacement aluminium windows for your home.
The only way to find out the actual cost of your project, is to have it measured up by a professional and then have a written quotation covering all aspects of the job, from supply to installation – and covering all the guarantees or warranties.
If you want to find out more, we can arrange for accredited independent installers to quote for you for free – just send us a few simple details about your project using our quote request form and we will be in touch right away.