Date posted: 30th November 2017

Flush sash casement windows

Window design has changed dramatically, forget unsympathetic installations, today’s window ranges combine style and sympathetic design, with ever improving levels of energy efficiency and security.

This includes a step change in the design of PVC-U window systems. A new generation of products allow window manufacturers to emulate the appearance of traditional timber flush casement windows in a thermally efficient and low maintenance window.

Supplied in a wide choice of timber and coloured finishes, including heritage shades, traditional tear drop and monkey tail handles and you get a product which is very difficult to distinguish from a traditional timber casement window.

Can PVC-U windows be installed in conservation areas?

Hampshire and surrounding counties have their fair share of conservation areas. In Hampshire alone, there were more than 300 at the last count. They’re there to protect the unique architecture of the county.

And while we would never recommend fitting a standard white PVC-U casement window into a period property homeowners do have options – even in a conservation area.

The rule is to talk to your local authority. The approach between building control departments can vary widely so it’s always better to be safe than sorry. This said, in most cases, the right choice of traditional replacement window, should meet with minimal resistance.

A short history of window design

Window deign in period homes generally falls into two categories, side-hung casements or sliding sash windows. Sliding sashes do what they ‘say on the tin’, and open with a vertical motion. Casements are more-or-less everything else. They’re side-hung and open and close in the same way as a door.

We’re going to focus here on more modern period properties – at least in historical terms. From the Georgian to late Victorian periods, sliding sashes were dominant.

Casement windows which had been popular up until the Georgian period, still ‘clung-on’ but tended to be restricted to rural properties. It was only in the late 19th century that they saw a resurgence, becoming the dominant window type by the early 20th Century.

If your property is Georgian, the chances are that it’s going to be Listed so any changes will need to go through an application process, with a general preference given to repair ahead of replacement.

If your home is Victorian or was built in the early part of the 20th Century, you may find that it now sits within a conservation area. This means you need to proceed with caution but replacement of windows is permitted in many cases. 

Residence 9

Residence 9 was the first low maintenance PVC-U window manufactured with a flush sash. It offers the opportunity to directly replicate traditional 19th Century window design in a heritage window – but the best part is, it’s virtually maintenance free.

It gets its name from its 9 energy efficient chambers. These deliver superior thermal and acoustic performance, also delivering far greater strength and improved security.

This means it achieves u-values as low as 0.8 W/m2K. This is the measure of heat loss and in this case, the lower the number, the better the performance. What it also means is that your heating bills are also significantly lower.

It comes with a wide choice of hardware, monkey tail handles and dummy peg stays, providing the fine detailing which makes it almost indistinguishable from a traditional timber casement replacement window.

We’re able to offer it as a mechanically jointed or welded finish. Mechanical jointing is carried out by skilled craftsmen who physically manufacture the window. This process offers the closest match to a timber window.

Residence 7

Residence 7, is a slightly more streamlined version of R9, the major difference that in case of R7, it’s 75mm deep as opposed to 100mm. This slimmer physique can be an advantage in 19th and 20th century properties as it’s a closer match to the depth of timber originals and that means that it’s less likely that you need to cut the plaster back.

The Deceuninck flush casement

Residence 9 was the original PVC system to emulate the appearance of a traditional flush timber casement window but a growing number of other window systems companies have followed suit and we’ve selected the best.

The Heritage Flush Sash from Deceuninck is the stand-out product. It offers exceptional sightlines and perfectly replicates traditional timber casement windows. It combines this with a top A+ Window Energy Rating, and exceptional weather performance -  all in a low maintenance window.

Again, we can offer two weld types. The infinity weld which seamlessly joins the window on a 45° angle inside and out a 90° butt weld, which replicates a traditional timber window joint. 

In common with R9 and R7, the Deceuninck Heritage Flush Casement is also available in a wide variety of colours – in this case more than 26 different woodgrain and colour finishes. This includes heritage creams, duck egg, greys and many more, which means that you can make the perfect choice for your home.

Flush casement timber windows

KJM also other a range of high quality flush casement windows manufactured from timber. We offer a choice of timber used, including Sapele, Accoya and Oak. Please find our timber flush casement  window web-page.

Also great for new properties

While our focus here has been on period properties, it’s also worth mentioning that they also look great on newer properties and even contemporary builds.

Colour and finish choice can give flush casements a very different appearance. Contemporary and highly popular anthracite grey, for example gives flush casements and altogether different personality.

Ultimately, it’s about aligning the design of your new windows to your property. What flush casements deliver is the flexibility to specify and develop a design that’s highly sympathetic to your home, especially if its older or in a conservation area at the same time as improving the thermal performance and security of your property.

Please don’t hesitate to get in touch to find out more by calling 01264 359355 or emailing email sales@kjmgroup.co.uk