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.
What is a Sash Window?
The word ‘sash’ refers to a single frame for glazing; a traditional sliding sash window features 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.
- Sashes were often arched instead of rectangular in Regency or Gothic revival periods, and it some regions it is popular to have horizontally-sliding sashes.
Should I Repair or Replace Sash Windows?
Be careful not to make the mistake of removing the original period timber sashes and replacing them with new models.
Always repair and waterproof existing sashes where possible, but there are many companies who will manufacture authentic replacements if the windows are beyond repair, or there aren’t any left in place.
What Material Should I Choose for a Replacement Sash Window?
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, plastic cannot realise the same tactile effect.
- An excellent insulator
- Long lasting (if properly maintained)
- Modern finishes are available in most paint colours and stains and mean that timber windows are no longer high maintenance
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.
- Low maintenance
- Energy efficient (but not sustainable as they cannot be recycled)
- Cheaper than timber (PVCu can cost around 40% less)
- Better quality models are more attractive and hard-wearing but difficult to repair
- Conservations are, in the majority, opposed to plastic windows
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.
- 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.
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Original timber sash and casement windows embody the charm and heritage of any period property, and that is why it is so important to ensure they remain in the best condition possible.
Draughts can be a common problem with original timber sash windows as they have a 3mm gap around the edge to ensure smooth operation. However, this does mean that heat escapes easily and wind, dust and water can enter.
Speak to a sash window specialist like Ventrolla, for advice on how to combat these common sash window problems without losing the appeal of their authentic charm.