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Last updated: 3 May 2024

Casement Window Replacement: A Complete Guide

casement replacement window

Casement windows are the most popular type of window in the UK due to their practicality and competitive prices. What’s more, some of these windows can last up to 50 years! Pretty impressive, right? However, to reach this longer lifespan, you’ll need to make sure that your windows are installed and maintained correctly.

In this article, we’ll talk you through the signs that you need to get your casement window replaced, the installation process, and what the standard casement window sizes are.

While we can give you a good idea of whether or not your casement window needs to be replaced, you can only get a truly accurate assessment from a qualified window installer. This is something we can help you with.

Don’t waste hours of your time researching and contacting local window companies near you one by one. Simply spend a minute filling out our short form and we’ll put you in touch with up to 3 installers from our network of professionals. Click the button below to get started.

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Do you need replacement casement windows?

Nothing lasts forever and we’ll all need to replace our home’s windows at some point. But how do we know when we’ll need a casement window replacement? After all, the lifespan of windows can vary from 10 to 50 years depending on how they’re made, the material they are made of, and how they are installed and maintained.

Below we’ve summarised some of the telltale signs of when you’ll need a casement replacement window.

When Do You Need to Replace Your Windows?
replacement window casement

There’s a draught

If it feels impossible to heat up your home no matter how high you have the heating on, then this could be an indicator that there’s a draught coming from one or more of your windows. The average cost of double glazing is worth paying in comparison to the money you might lose from heating costs.

In some cases, it will be obvious where the cold air is coming into your home. But if it’s not obvious, you can hold a candle beside each of your windows and see if the flame flickers to tell whether or not there’s a draught.

A draught is usually a sign of a broken seal. However, you can’t just replace the seal. You will need to replace the glass unit or the entire casement window.

Condensation between window panes

Not all condensation is cause for concern, but if you have double or triple glazed casement windows and see condensation between the panes, this is a sign of a broken seal. If you don’t get a casement window replacement quickly enough, this will lead to more moisture. And in extreme cases, this could lead to mould, which could be detrimental to your health.


If it’s pouring down outside, you may notice water leaking through your casement window. A leak could lead to mould and rot, especially if you have wooden windows. It is also dangerous if you have any electrical items near your windows – remove these items as soon as possible before any potential damage.

Increased noise levels

If you’ve noticed that sounds from outside are disturbing you more often, then this is a sign to upgrade your windows. Especially if you only have single glazed windows, then getting double or triple glazed windows should make a world of difference in terms of sound-proofing.

However, if you already have replacement double glazed windows and are still having problems with noise, then you may have a broken seal that needs to be attended to. Alternatively, your window may not have been installed correctly in the first place. This is why it’s so important to find a reliable installer.

At GreenMatch we have an entire network of reliable and professional window installers based across the UK. Simply click the button below and we’ll put you in touch with up to 3 qualified installers in your area.

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window casement replacement

Your windows are physically damaged

If you see chips or cracks in your window pane, no matter how small they may seem, this indicates that you should get a casement replacement window soon. Chips and cracks will make your home less energy efficient and increase your heating bills.

Increased energy bills

Maybe you haven’t noticed any obvious signs of damage on your casement windows but you’ve definitely noticed your heating bills increasing! This could be due to a variety of reasons, but it’s worth inspecting your windows more closely to ensure they’re not the culprit.

Difficulty opening and closing windows

Your casement windows should open and close without any difficulty. If you’re having trouble with this, there could be multiple reasons why. It may just be that the window hinges are stiff and require an industrial lubricant such as WD-40. However, it could also signal that your windows are misaligned. This may be due to poor installation or simply because of gravity acting on your window’s hinges over time.

The latch or handle on the window is broken

Window latches and handles can break due to wear and tear over time or because of too much force. It should be possible to replace the latch or handle of your casement window, but if your window is 20+ years old or has any other issues, it may be more worthwhile to replace the whole window.

Can casement windows be replaced?

Yes, casement windows can be replaced – and should be if you’re experiencing any of the problems mentioned above. If your windows are energy-inefficient, you may even be eligible for window replacement grants.

And even though casement windows can last a long time and you’re not experiencing any significant problems, you still may want to upgrade your windows. Installing modern windows could help raise your property’s value, as it keeps up with current trends and increases your home’s energy efficiency rating.

Whether or not you have a problem with your windows that needs to be fixed quickly, we can help you. Our team at GreenMatch can help save you stress and hours of your time by finding you certified casement replacement window companies near you.

You’ll receive up to 3 free quotes, which you can objectively compare and choose the best deal. Click the button below to get started.

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The casement replacement window process

Figuring out how to install a replacement casement window is not an easy task – that’s why it’s best to leave the job to the professionals. Every window replacement will vary depending on what type of window you currently have and what type of window you want to install.

For example, box-type sash windows usually have a much thicker frame compared to casement windows. Therefore, removing plaster will likely be required in order to make the gap around the window smaller for the casement window replacement to fit.

how to install a replacement casement window

We’ve summarised the whole process of getting a casement replacement window in 5 small steps so you can know what to expect:

  1. Find installers: It’s important to find a qualified installer in your area so that you can feel assured that your window replacement will be fitted correctly. However, beware that some installers may overcharge you. It’s recommended that you compare quotes from multiple installers to ensure you’re getting the best deal.
  2. First home visit: After deciding which installers are worth your time, you can set up an appointment for each one to visit your home and assess what is needed.
  3. Review formal quotes: After the home visits you will receive formal quotes from each installer. Now you can compare the quotes and choose an installer. You will likely have to put down a deposit of 10% or 20%.
  4. Confirm dates: Your installer will clarify how long the process will take. You can then decide together on a date for the installation to take place.
  5. Make the final payment: After the installation has been completed and you are happy with the result, you will make the final payment. You can now enjoy your new replacement casement windows.

How long the installation will take depends on how many windows you are getting replaced and whether it is a like-for-like replacement. If you are having multiple windows replaced, it is usually recommended that you replace them all at the same time, especially if the point is to improve your home’s energy efficiency.

Skilled installers can replace a standard window in as little as 30 minutes. Although, if you want to install a larger custom-made window, it may take one or two days.

Generally speaking, an experienced window installer can replace between 10 and 15 windows per day. However, if, for example, you opt for wooden windows that need to be primed and painted, this will naturally take more time.

To help speed up the process, you can prepare your home beforehand by clearing the area around the windows. This makes it easier for the installers to access the window and ensures that none of your belongings will be damaged.

If you’re ready to begin the process and don’t want to waste another minute, we can help you. We’ll send you up to 3 free quotes from certified installers near you. 

You can compare them side by side and objectively choose the best deal, meaning you don’t need to worry about being ripped off. You are also under no obligation to accept any of the quotes you receive. Click the button below to get started.

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What sizes do casement windows come in?

Casement windows come in a variety of sizes. It’s a good idea to know what size you’ll need before you start the process. By taking measurements of the window you’d like replaced, you’ll be able to better describe to the installer what kind of window you want, meaning the initial quote they give you will be more accurate.

In the following table you can see what some of the most common sizes for casement windows are in the UK.

Common sizes for single casement windows
25 x 35 in635 x 890 mm
29 x 74 in736 x 1194 mm
29 x 59 in736 x 1498 mm

If you want a window that is particularly large or has a unique shape, it’s best to discuss this with the installer first to see whether they can assist you or not.

Get the best casement window replacement prices

A casement window replacement cost can vary depending on multiple factors, such as the frame material, window size, and number of windows you need. However, it also depends on factors unrelated to the product, such as your location and installer’s rates. This is why it’s crucial to compare quotes. This will give you the peace of mind that you’re hiring a reliable installer at a great price.

However, one common problem when it comes to comparing quotes is that it can take a long time to find them. Researching and contacting different installation companies can take up hours of your time (and also isn’t the most exciting way to spend your weekend). Thankfully, our team at GreenMatch can help you with this.

We can quickly put you in touch with up to 3 qualified installers in your area from our professional network. You’ll receive quotes free of charge from each installer within 48 hours, which you can then easily compare side by side and choose the best one for you. And don’t worry – you’re also under no obligation to accept any offers you receive.

Click the button below to get started and have your new windows fitted as quickly as possible.

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Frequently Asked Questions

Bronte McClelland
Written by Bronte McClelland, Writer

Brontë is an experienced writer and editor for GreenMatch. Her passion for sustainability and renewable energy drives her to stay at the forefront of green-energy trends.

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