What is a Casement Window? Styles, Designs & Sizes

Casement windows are one of the beautiful window styles commonly found on older British homes. They are renowned for their simplicity and functionality, but there is more to casement windows than meets the eye. Like most domestic fixtures, they come in a range of sizes, styles and designs, and require certain maintenance to keep them working well. Read on for our guide to casement windows.

A window to the past

Historically, casement windows have been one of the most popular British window styles. They rose to prominence in the 18th century as a replacement for stone mullioned windows, with Georgian blacksmiths crafting the original window frames from iron.

These handcrafted frames were also fitted with a number of lead strips to hold glass together. Why? Manufacturing glass wasn’t quite so advanced in the 1700s. The large panes of glass we see today were essentially impossible to produce. This meant using several smaller glass panes – usually six – to make up a full window.

Because of problems with the iron frames – both aesthetically and functionally – they were gradually replaced by timber. And by the start of the Victorian era in the 1830s, there were no more iron frames being produced. Oak was the most common material following iron, and even the lead strips were replaced with wooden glazing bars to hold glass in place.

The use of glazing bars allowed putty to be inserted to hold the panes in place more securely. And over time, with enhancements in glass manufacture and window production techniques, larger panes of glass became an option. Consequently, new casement windows were made up of only two panes of glass.

Becoming commonplace

This seemingly perfected design was by far the most popular during the 19th century. It was only in the late 1800s that sash windows began to take over. The sash design took advantage of more modern glass manufacturing which allowed larger sheets of glass to be made. Though with such historic value, it was inevitable casement windows would be re-introduced a few decades later.

In the modern day, we can see a huge range of casement windows from periods gone by, which are still functioning well and in great condition. But there has also been a rise in uPVC casement windows of late. Presented as a modern alternative to the wooden variety, uPVC casement windows come with a range of drawbacks like their unauthentic appearance, lack of versatility when it comes to design and the false economy arising from further replacements down the line.

The benefits of casement windows

Owners of properties with casement windows installed will enjoy a number of benefits from the traditional British fixture. Their method of opening offers multiple perks on its own…

• Ventilation: Casement windows are hinged to the side with a full outwards opening. This means, firstly, that you can maximise the natural ventilation of your home. It’s particularly useful in the summer because it will keep your home cool without the need for artificial air conditioning and fans.

• More space: But this outwards opening also means no obstruction to your home. With no need to leave space for the sash swinging open, you can design your room’s layout more freely. Most casement windows also use single-lever or tandem latches. This is advantageous simply because it makes them easy to operate. Windows can be opened and closed without any hassle, making them ideal for utilising the most of your space.

• Cost efficient: With wooden casement windows, you also benefit from long-term cost-efficiency. Quite often, problems with uPVC windows are not repairable because they cannot have individual parts changed. A full window replacement is often necessary to fix even small issues. But with wooden casement windows, any damage can be isolated and replaced or repaired. Your problem will be eliminated with ease, without the need for costly replacements.

Casement window sizes

Because of the modifications over time, casement windows cannot be narrowed down to one specific style in the modern day. Changes in glass manufacture, house structure and simply design trends mean that we now have a number of areas in which casement windows can vary.

The most obvious area is size. Casement windows come in a whole range of heights and widths. But there are some standard sizes amongst the variety. Windows have been developed based on the bricks surrounding them – the height of which is 150mm, for two brick courses (including mortar). Consequently, the standard height of casement windows starts at 450mm and rises in lengths of 150mm to 600mm, 750mm and so on.

Width is slightly less standard. Changing brick sizes have resulted in different sets of standard window widths. Generally, they have either been made to fit bricks of 215mm or 300mm in length. And there is further variance because of multiple casement windows, which can make some frames much wider than others. Standard sizes aren’t too important though. Most window suppliers will offer bespoke services as well as a collection of ‘standard’ options.

Changing designs

Another result of changes over time is the variety in casement window design. Some of the biggest changes to casement windows occurred in the Victorian period. Despite the Gothic era running from the 12th to 16th century in France, the architectural style inspired some changes in 19th century Britain. As a result, there are still some casement windows boasting Gothic arches today.

More commonly, however, casement windows vary simply by the glass type. Some of the more modern windows will be fitted with a single pane of glass. But far more commonly, they are made up of two or six panes. Here are the main types of casement window:

• Two-paned: Two panes of glass connected by a single horizontal glazing bar
• Six-paned: Six panes of glass with multiple glazing bars both horizontal and vertical
• All bar: The style of the six-paned window replicated for bigger spaces. More glazing bars and more panes
• Horizontal bar: Much like the two-paned window this style only uses horizontal glazing bars, but has more than one bar for more panes of glass
• Cottage: Cottage casement windows have four panes of glass with vertical and horizontal glazing bars forming a cross in the centre
• Deco: A single pane of glass on the bottom section, with several panes in the window’s top section
• French casements: Also known as French windows or a double casement, this is where two sashes are hinged on opposite sides of the frame. They open separately and meet in the middle to close.

How do I maintain my casement windows?

Like most things in your home, casement windows require some maintenance every now and then. These are simple steps to ensure your windows keep working well and continue to look great. Number one on the list is lubrication. Because casement windows open on a hinge, you need to ensure this hinge doesn’t become stiff or rusted.

A light penetrating oil is the solution. This will prevent hinges sticking. And the same goes for your window’s handles or catches. Be wary of lubricating them too much, though. Too much lubrication can cause hinges, handles and catches to operate too loosely. Once a year should suffice.

A big part of maintaining your wooden casement windows is ensuring they are protected from the elements. There are two key areas to check – paint and sealing. Your windows need full coverage from paint to prevent water getting into the frames. If the paint is flaking or cracked, it can allow water to penetrate the timber. Over time this could lead to decay and rot.

Similarly, if the sealing is broken around your window’s glass panes, this can result in water ingress. Causing rattling, draughts or even decay, this is another problem that can develop the longer you leave it. Ensure you don’t face problems like this by inspecting your windows every year or so and getting a professional window inspection every few years.

Casement window replacement

If your casement windows have incurred damage or been left to decay, you might be wondering whether you should get them replaced. With uPVC windows, this might be the only option. But with strong wooden windows, this is only the last resort. Whatever the damage, wooden window restoration offers a long-term alternative to costly replacements.

Wood decay? The problem can be isolated and eliminated by replacing individual wooden panels. Paint problems? A professional paint service will ensure your windows are fully protected and will stay protected long into the future. A good restoration company will even be able to deal with glass damage.

Wooden window specialists

At Fortis & Hooke, we have a passion for restoring original wooden windows and doors. Our team of expert carpenters, joiners and glazers have developed specialist methods that make even the most ambitious restoration projects fully possible. It’s thanks to them that we can offer a cost-effective alternative to needless replacements.

Whether it’s glass damage, repainting or even wood decay, we’re fully equipped to deal with it, meaning you can keep your home’s beautiful heritage features. For more information, call us on 0800 313 4688 or get in touch online.