Grade II listed building with slimline double glazing

Preserving the character and historical integrity of listed buildings is paramount when considering any alterations, particularly when it comes to window replacement. Obtaining Listed Building Consent is crucial, as it ensures that any proposed changes respect the heritage value of the property. In this guide, we delve deeper into the process, offering specific tips when it comes to getting planning permission for new windows on a listed building.

How to obtain listed building consent

Listed buildings hold significant architectural or historic interest, as recognised by organisations like Historic England. These properties are protected to safeguard their unique character, ensuring they remain for future generations to appreciate.

Timber windows on listed buildings can only be replaced or restored with planning permission, or ‘Listed Building Consent‘. When granting listed building consent, planning officers are looking for evidence that you understand the importance of preserving the character of the building as far as possible.

Here are some key points to consider when making a listed planning application for windows:

1. Restoration or replacement?

Historic grade II listed property in Isleworth, LondonIf your property has the original period windows with the original glass in them, it is unlikely that you’ll get planning permission to change the original windows completely, if they’re in a restorable condition.

However, careful restoration and draught-proofing would be more likely to be approved, which will help to retain the look and character of your property while being more cost-effective than full replacement. If windows are beyond repair, replacement may be necessary for the long-term preservation of a listed building.

2. Planning applications – Build a solid case

If you’re asking to fully replace your windows, you need a ‘justifiable cause’ why you’d like to replace them.

This justifiable cause could be that the windows are beyond economical repair. For example the rails have rotted away, or there is significant rot and decay. In this situation replacement rather than restoration could be the best long-term solution for the property.

Another justifiable cause is if the windows have already been replaced, but in an inauthentic or inappropriate way. This could involve not using the original material, or using the wrong glazing bars for example, so you could suggest that they could be changed back to something closer to the original windows.

3. Planning applications – Be honest

If your property has, for example, two original windows in reasonable condition, it will help your case to be honest from the start and say that two could be saved. Don’t just say they’re all in poor condition and need replacing. Planning officers are more likely to agree to a combination of repair and replacement than just replacing all the windows. Even if you’re asking for all of the windows in a listed building to be replaced, be open and honest and explain that it may be possible to save two of the windows.

4. Use listed windows experts

Specialist listed window providers such as Timbawood are able to provide exact-match heritage windows that will stay faithful to the look of the property and any neighbouring properties. Mention you are using a specialist window restoration company with experience of working with sensitive buildings when replacing windows in a listed building in order to help your case.

Specialist materials such as restoration glass can be used – which has the slightly uneven look of period glass compared to the modern flat look – and the windows can be hand puttied and hand painted, and fitted with either single glazing, or slimline double glazing that looks like single glazing, to complete the period look.

5. Provide photos and CAD drawings

CAD drawings casement windows

Provide photographic evidence of what your windows look like now, and ask your window provider for a set of CAD drawings – one as the windows look now, and the other as they will look after the replacement. This should show the planning officers how closely the replacements will match the originals.

How much does it cost to replace windows in a grade II listed building?

Determining the precise cost of replacing windows in a Grade II listed building can be challenging due to various factors. Generally, renovating windows in Grade II listed properties tends to be more cost-effective than outright replacement. Renovation projects typically require less time and fewer materials compared to full replacements, leading to lower costs.

If windows do need replacing, a more cost effective option is ‘part replacement’ – where only the moving parts of the window are replaced, and the original frames are retained (and repaired if necessary).

Remember, every case is different and there is no guarantee that your planning application will be approved.

To find out more about planning applications, and to download an application form visit your local authority website.