What is a Sash Window?
There are 2 basic types of Sash window:
- Single hung – where one sash casement slides (usually the lower one)
- Double hung – where both sash casements slide up & down
Having a double hung sash windows allows both sections to be partially opened to create a nice circulation of air into, and out of, the room.
There are some examples of triple hung sash windows, but these are few and far between – not for your average 3 bed-semi or 4 bed detached!
The weight of the windows is counterbalanced by cast iron weights built (boxed) into the side frames – hence the sometime use of the description “box-sash window”.
Why UPVC Sash Windows can be better than timber?
Over time, these timber frames may deteriorate through warping or even rotting, which can leave sliding window casements loose in their settings. This poor fitting ends up contributing to damp ingress, draughts and poor security.
The other perennial problem is with the counterweights either coming lose or the sash rope connecting them to the moving casement wears through and breaks.
Modern uPVC sash windows can be fitted to use spring tension mechanisms in place of the rope & counterweight system.
Obviously, one solution could be to get a crafts-person in to asses and repair all the faults, but in many cases the window repair costs are quite high – running into hundreds of pounds, especially where it is a major overhaul.
A cost effective and complete solution would be to remove the timber window and replace it with a modern uPVC Sash window.
Benefits and applications of a uPVC window frame
uPVC stands for “unplasticised polyvinyl chloride”. It is related to PVC, but since no plasticisers are added to the material, it is less pliable and stronger than PVC. This makes it particularly durable and resistant to harsh weather conditions. It is also highly resistant to expansion, warping, contraction and does not rot.
Replacing a window will give you the option to go for double glazing as well, which will help you prevent a lot of energy loss which is a big problem with older single glazed timber sash windows.
A replacement uPVC sash window frame can be made to fit the style of your current windows exactly, so that you can maintain a sense of consistency and uniformity, even if you decide to only replace a few frames. Victorian period homes tend to feature Sash windows, especially where they are bay-fronted houses.
Any professional window manufacturer will be able to perfectly measure and mimic the design of the original window. This will also make it easier to get permission for a restoration if you were to need one, because the new window frames will still be in line with the historic appearance of your home.
A uPVC frame can also be made in a variety of colours, which adds to its resemblance to the original wooden frame. Those colours can also be textured to recreate & mimic the appearance of timber, so good in some cases that it’s difficult to tell the difference between the two from any kind of distance.
What are the advantages of a uPVC replacement Sash window?
In general, uPVC sash windows cost considerably less than wooden window frames.
uPVC frames are far easier to clean than wooden frames, and require little other maintenance. Because they are so resistant to degradation, not only does this make them highly user-friendly, it also means they are a better investment than a wooden replacement, as wood will still be prone to warping and need painting regularly and the uPVC Version should outlast it.
In addition to this, uPVC sash window frames can actually help you save money, since they are typically built to be more energy-efficient than a standard wooden frame. Featuring multi-chambered frames that resist heat transfer and a drainage system to redirect water (rather than absorbing it like timber) these windows systems are purpose built to more than meet todays’ energy efficiency demands.
Tilt & turn sash windows
However, a disadvantage of going for a cheap uPVC sash window replacement is that it may eventually decrease the appeal of your home (if you ever want to sell it), because many people do still prefer the idea of traditional wooden frames.
Still, a wooden frame requires a lot more maintenance than a uPVC model in order to meet the same standards, so the ease of use and energy-efficiency of a uPVC replacement sash window is well worth considering.
Sash windows do have some limitation on the maximum “use-able” width for day to day living. The bigger the window, the heavier and more effective the counterbalancing system needs to be.
As a general “rule of thumb” a large example sash casement without a mullion would be around 1200mm wide with a height of around 1400mm.
How much do UPVC Sash Windows Cost?
As usual, you will need to take into account variations on design elements, such as size, glazing. Colour etc., but as a rough guide here are some uPVC Sash window prices.
Because labour costs are such a variable, some of the prices below are aimed at those for supplying the window without fitting
|WER (energy rating) & Size||Basic Design||Average Sash window prices|
|600mm x 1000mm – B WER||single hung white uPVC||Starts at £400 – fitted|
|900mm x 1000mm – B WER||single hung coloured uPVC||Starts at £300 – supply only|
|1200mm x 1000mm – B WER||single hung white uPVC||Starts at £550 – fitted|
|1500mm x 1000mm – B WER||single hung white uPVC||Starts at £350 – supply only|
- You can probably add in the region of 10% to 15% for a coloured or wood grain surface finish
- More Window Price Guides
- UPVC Casement Windows Design & Styles
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