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Wooden Sash Windows vs Plastic

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Wooden Sash Windows vs Plastic

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Published on: November 25th, 2021

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Which is best – wooden sash windows or uPVC?

Find out which is best for your home – wooden sash windows or uPVC sash windows. There are lots of different reasons to choose wooden sash windows. In this blog post we’ll show you how timber sash windows are better for your home, your wallet and the environment.

What are wooden sash windows?

We will be looking at Gowercrofts wooden sash windows range. Remember, not all wooden windows are the same and there can be massive differences in quality depending on the materials used and the manufacturer. 

Gowercroft timber windows are superior to many other manufacturers (and we have awards to prove it!) because we use ethically sourced wood of the highest quality. Our workshop in Alfreton, Derbyshire is environmentally friendly and we have a highly skilled, passionate workforce who have developed and perfected the production of timber windows.

What are uPVC Sash windows?

We’re running a comparison on a generic uPVC sash window as most plastic windows are made from the same materials from a few different suppliers. Of course, the individual manufacturers may have different standards in putting the pieces together, but generally there is little difference between one supplier and another.

So let’s get started – wooden sash windows or plastic – which is better?

Wooden Sash Windows last longer

Gowercroft wooden sash windows have a very long expected lifespan. This is down to the materials used and the manufacturing process.

The Materials

Gowercroft windows are made with modern timbers such as Accoya® and Red Grandis. These are timbers that are specially treated to expand their lifespan – Accoya® timber has a 50 year warranty (25 years if used in the ground or fresh water – still pretty impressive!). 

The treatments the timbers go through make them much less impervious to water ingress. They also have a much reduced expansion and contraction rate from temperature, which means that less water can penetrate the wood. This lack of movement also is kinder to the paint or varnish – it’s the seasonal expansion and contractions that cause the coatings to crack and allow water into the wood. Basically, we have a water proof wood that preserves its protective coating.

Read more about Accoya® here on

The Manufacturing Process

With such good quality timber, then the manufacturing process has to be just as good so as not to create any weaknesses. Joints must be perfectly matched and the minute details of window bars, seals and even how the ironmongery is fitted can make a difference. Incremental improvements in our processes over time have resulted in near perfect construction.


The finishing touch is to coat the timber frame in either paint or varnish. At Gowercroft we use special microporous paint that allows the wood to breathe without allowing any moisture in. This extra protection will ensure the windows have the longest possible lifespan.

Another advantage of all this is that the windows will been very little maintenance throughout their life. It’s the constant cycle of expansion and contraction plus water ingress and freezing that makes the paint peel from wood. We’ve ensured that this has been all but eliminated.

Expected lifespan of Gowercroft Winston Wooden Sash Windows – 70 to 80 years.

UPVC windows are not as impervious to the effects of temperature expansion and contraction. Whilst there is not paint to flake or fade, the constant movement of the frame takes its toll and eventually the seals on the windows will start to fail. If any inferior materials are used – for example the seal between the glass and the frame can become brittle and allow moisture into the innards of the frame – this is somewhere water shouldn’t be an this will accelerate the deterioration of the window.

Expected lifespan of a good quality uPVC Sash Window – 20 to 30 years.

Purchase Cost vs Long Term Savings on Wooden Sash Windows

Yes it is true that good quality timber windows will cost you more to install than their plastic equivalents. However, when the service life is taken into consideration, you will have to replace your plastic windows at least once, maybe twice during the expected lifespan of the wooden sash windows. So straight away you are going to have to spend a lot more money in replacing your windows every 20 years or so – and don’t forget the mess and hassle involved too.

Wooden Sash Windows are better for the environment

We at Gowercroft have undertaken extensive research into the environmental effects of wooden, aluminium and plastic windows with help of Derby University. The study covers the production of windows from cradle to gate. Unsurprisingly, timber windows are better for the environment – but the study revealed that Gowercroft windows actually help improve the environment because of the time it takes to grow the trees. The sustainable forests that the timber comes from are good for the environment, and none of the positive effects are reduced by the transportation and manufacturing processes.

Additionally, Gowercroft have taken steps to ensure that our workshop is as environmentally friendly as possible, for instance with our biomass heating that runs on timber offcuts.

Read more here:

In contrast, plastic and aluminium windows have a very bad effect on the environment just from the raw materials extraction processes. Add to this the fact that the manufacturers may not be as conscientious as we are. There are also the problems with recycling the windows at the end of their (shorter) lifespan.

Read the full study here:

In conclusion

It seems that there is a very strong argument for installing good quality wooden sash windows over their uPVC equivalent. Both the environment and financial benefits make the decision a no brainer. Add to this the fact that wooden windows just look better that plastic and add an air or quality and sophistication to any property, then it seems there is little doubt: if you want to save money, help preserve the planet and have a great looking home for years to come, fit wooden sash windows!