Sash windows are a must-have for many self-builders, renovators and converters as they provide an unparalleled glimpse into past traditions, but it is as important to consider the function of the window as much as it is the style.
An inherent part of British architectural history, any styled property from the 17th to 19th centuries would be lacking without them so if you’re renovating a Georgian, Regency or Victorian property, this item should be high on your shopping list.
The word ‘sash’ refers to a single frame for glazing and the traditional sliding sash window is usually made up of two sashes that slide up and down.
Styles of Sash Window
When deciding on sash windows for a period property, you must be careful to get the time right as there were several developments and style changes in sash windows over the years.
- Venetian windows consist of a central sliding sash with two fixed panes
- The Queen Anne Revival styles incorporates several panes in the upper sash but just one or two in the lower.
- For Regency or Gothic revival periods, sashes were often arched instead of rectangular and it some regions it is popular to have horizontally sliding sashes.
Be careful not to make the mistake of removing the original period timber sashes and replacing them with new models. Where possible, existing sashes should always be repaired and waterproofed, but if the windows are beyond repair, or there aren’t any left in place, there are many companies who will manufacture authentic replacements.
What Material Should I Choose for a Replacement?
For traditionalists or for those living in a Conservation Area or listed building, genuine timber sash windows are likely to be the first and only choice. Sadly, the same tactile effect can’t be realised in plastic.
Wood is durable and an excellent insulator and, if taken care of properly, a timber frame can last for centuries. A common misconception is that timber windows are high maintenance, but with the use of modern finishes – available in almost any paint colour or stain imaginable – they really don’t require a lot of upkeep, just some periodic maintenance and to be examined once a year for cracked, flaky paintwork and decay.
PVCu is often used as a substitute for painted wood. Though most commonly seen in white, it comes in a wide range of colours and finishes, including a photo-effect wood finish. It is low maintenance and energy efficient, though it can’t be recycled.
When bought off-the-shelf, PVCu is usually far cheaper than timber, which can cost as much as 40% more. Many conservationists are opposed to plastic windows, but the better quality models can be attractive and hard-wearing, though they are difficult to repair.
It is becoming popular for sash windows to be composite in their construction, with timber on the interior, but clad with aluminium on the exterior. This ensures they retain the classic look of wood on the inside, but outside are extremely low-maintenance and are able to withstand all weathers.
Glazing in Sash Windows
Sashes traditionally consist of a number of small panes, or ‘lights’ that are held together by glazing bars to create a larger glazed area. This is because glass advancements at the time didn’t allow for very large expanses of clear glazing.
The number of panes depended on the era: ‘six over six’ is quintessentially Georgian, though larger ‘eight over eight’ windows were also common. In Victorian times, ‘two over two’ reigned supreme, but throughout the whole period, many other configurations were seen, as well as the inclusion of sidelights.
Modern building regulations make it near impossible to have single glazed windows on a new house, so you may have to sacrifice true authenticity. It is, however, possible to install single glazed windows on many renovations.
Dividing up small units of double glazing with thick bars tends to look clumsy, but there are ways to effectively recreate fine glazing bars. The best way is to bond mock bars onto either side of a single double glazed unit. You could also incorporate spacer bars between the glass sheets, at a higher cost, to add to the effect.