Can You Replace a Window Without Replacing the Frame?

triple glazed bay windows

If you have a broken or deteriorating window, you’ll undoubtedly be looking into types of window replacement. Depending on the condition of your windows, you will have different options open to you. If your frames are in good condition, you can replace the window without replacing the window frames – this is known as a pocket window replacement. However, if your frames are aging, it will be best to opt for full frame replacement windows.

We’ll take a look at the different replacement window options, their pros and cons, and when to choose each kind of replacement below. 

Choosing Window Replacements

When your windows need replacing, it can be a chance to fully embrace the change. You can pick a new style of window, one that fits your tastes or the design of your home better. In addition, you can pick a more efficient, insulating window replacement, one that performs better and lowers your bills.

On the other hand, all the options available can be overwhelming and it can be time-consuming trying to find the best choice. For most people, it’s less of an opportunity and more of a hassle. Potentially an expensive hassle. Many people just want the quickest, cheapest option. Their instinct will be to get a like-for-like window replacement and be done with it.

Most people only know of full frame replacement windows, but did you know there could be an easier way to replace your windows where you keep the existing frame? A pocket window replacement allows you to replace your window without having to replace the window frame.

It’s not suitable for every situation, but it is a more cost-effective solution if your window frames are still strong and stable.

What Is a Full Frame Window Replacement?

A full frame replacement involves taking out the entire window and frame. Even the trim is removed, everything right down to the walls of your home.

It’s a complete fresh start for your windows, allowing you to change the material, appearance and style of your window.

Pros of Full Frame Replacement Windows: 

  • You will be left with a far more energy efficient window. Firstly because the sash-to-frame fit will be a lot closer (as they were manufactured to match), but also because it allows the chance to add insulation around the window opening.
  • It exposes the rough opening of the window, allowing a chance to inspect it and address any issues, like damp or rot, that might shorten the life of your window otherwise.
  • You will keep the full breadth of the window glass.


  • It is more expensive as it is a more complex job. It isn’t just the cost of the extra frame – the work takes more time, and potentially more manpower, all of which contributes to an increase in price.
  • It is more disruptive. 

What Is a Pocket Window Replacement?

Also known as an insert window replacement, a pocket window replacement is when only the interior frame (or sash) of the window is removed. A new window is then ‘pocketed’ into the old frame. 

Pros of a Pocket Window Replacement: 

  • It is cheaper – not only does it involve less materials, it’s also a quicker job.
  • If your window frame is still fully functional, it is less wasteful.


  • It can mask potential issues in the frame, such as wood rot or damp in the rough opening.
  • Even if your frames are stable at the time of the pocket replacement, they will still need replacing eventually – potentially long before the insert window does.
  • By inserting a new frame into an existing frame, you will lose some of the glass size of the window. This will affect how much light the window lets in.

When to Choose a Full Frame Window Replacement

Obviously, if you want to dramatically alter the appearance of your windows then your only option is a full frame replacement. If you want to switch from casement to box sash windows, or similar, even if the window is the same size, a new frame will be necessary to house the opening mechanism.

However, appearance isn’t the only deciding factor. You can only choose an insert window replacement if your existing frames are still in excellent condition. If your frames are even slightly cracked, chipped or warped, they could be compromised and it wouldn’t be worth using a pocket replacement, as the frames would need to be replaced soon enough anyway.

If there is rot present anywhere around the window, including the frame, sill, trim or casing, then you will have to go for a full frame replacement. The rot will weaken the frames, and could spread to the insert window. A pocket window replacement on a less-than-perfect-frame is a waste, as it will have to be fully fixed later.

When a window gets damaged, the prospect of replacing it can be daunting. Choices will need to be made, money will need to be spent. With a pocket window replacement, you have the option to spend a little less, while still keeping your home safe and warm. However, if your window frames aren’t good as new, it is best to opt for a full window replacement. This will allow top performing windows in terms of insulation and security, and ensure you don’t need to do more work in the near future.

We offer a wide variety of high quality replacement windows. From our top of the range, high performance JELD-WEN windows to our own timber windows & aluminium windows, there’s something for all properties. Get in touch with any enquiries.