Many home extensions and renovations are designed to be contemporary in their appearance and boast large windows and doors. This is reinforced by the various home renovation programmes where the finished project will often demonstrate large sliding doors and more recently large opening and fixed light windows.
If you are considering large windows there is a choice of aluminium window systems to choose from. With many of the leading systems companies having a range of casement windows to suit both traditional and modern homes, extensions or other projects these may require large pieces of glass fitted to bigger windows than normal With some window systems, already large opening windows can be made even larger as some systems offer a “heavy-duty” sash or vent section (the part of the window that opens) to enable big square top hung casement windows or side hung windows to be manufactured.
So if you are looking at big glazed screens with large opening windows what are the typical sizes available to you?
What are the minimum and maximum aluminium window sizes?
In this article we will use the standard casement window offerings from some of the leading aluminium systems companies such as SAPA Building Systems, AluK Systems, Smart Systems, Schuco Aluminium Systems and the new Origin Aluminium Window. There are of course many other window systems available, but these are the most widely used products in residential properties in the UK today. Some of these systems are available with either a commercial or residential suite but for the purposes of this article we are looking at typical residential systems.
If you are looking to construct a bespoke screen or are looking at ways of having the largest possible opening windows, then the following chart will be useful.
| System | Top Hung Window | Side Hung Window | Heavy Duty Top Hung Window | Heavy Duty Side Hung Window |
|---|---|---|---|---|
| SAPA Crown Casement Window | 1200×1336 | 736×1336 | n/a | n/a |
| SAPA Dualframe Casement Window | 1200×1200 | 700×1300 | 1600×1500 | 838×1829 |
| Schuco ASS 70 Casement Window | 1400×1200 | 700×1400 | 1800×1800 | 700×1600 |
| Origin Casement Window | 1500×1500 | 1000×1800 | n/a | n/a |
| AluK 58BW Window | 1500×1500 | 700×1500 | subject to hardware | subject to hardware |
| Smarts Alitherm 600 Window | 1400×1500 | 1000×1400 | n/a | n/a |
| Seniors SPW 600e | 1500×1500 | 900×1500 | n/a | n/a |
| Metal Technology | 2000×2000 | 1000×1800 | subject to hardware | subject to hardware |
*All sizes given are opening light sizes and not overall window sizes.
*Information given is a guide only with approximate sizes based upon specific hardware. Advice should be sought with your supplier as to the feasibility of large opening windows within your own project.
5 Things to consider if you are thinking about large windows
- The larger the window, the heavier it will be. Most systems companies whilst offering minimum and maximum window sizes have conditions based upon the overall “sash weight”. It is very important to remember that friction hinges or friction stays are what hold the opening vent to the outer frame and it is these hinges that take up all the weight, stresses and downforce when the window is fully open.
- The choice of glass will also affect the overall weight of the window.
- The larger the window the larger the projection outwards. This is particularly the case on top hung opening windows that have the handles at the bottom and project outwards. Some of these aluminium systems can create very large windows indeed and you will need to consider how far out a large window will actually open. In many cases such large windows are fitted with restrictors to prevent them fully opening outwards with a release function on the windows to enable to open out further.
- Many fixed windows are possible at overall areas of approximately 5 square metres but this is dependant upon the individual window design and maximum sizes of glass possible.
- There are many aluminium systems available and some systems companies can even create bespoke windows therefore always seek professional advice as to what windows will best suit your own wishes or contact us and we can give you further information.
What is better for large windows? Aluminium or PVCu?
It is already well known that aluminium has inherent strength which is why it is the preferred choice for windows in modern construction projects. Aluminium has been used commercially for many years already as commercial buildings will typically have larger windows and glazed screens than most houses.
Aluminium windows are typically two and a half times stronger than PVCu. What this means for the customer is that whilst aluminium windows have much slimmer sight lines than any timber or PVCu window they can actually support substantially larger panes of glass and glass areas even with their much narrower frames.
Therefore using aluminium for your windows not only gives you slimmer stronger windows but larger windows with more glass to look through and arguably more attractive windows with less visible bulk.
