About this guide
This guide has been created based on our experience of working within the various London boroughs, but the same logic and rules loosely apply across all of England, Scotland and Wales. It is intended for guidance only, you should always check with your local authority before making any alterations to your home.
Do I need planning permission to change windows and doors in London?
Category 1 - Houses, flats, and offices which are NOT in a conservation area or listed.
The Quick Answer: Planning permission is NOT needed for houses. Planning permission is USUALLY NOT needed for flats and offices, but this is decided at local level and is at the discretion of your local planning authority.
You do not normally need planning permission to change your windows and doors as this is considered ‘permitted development’ for houses.
Flats and offices do not ‘technically’ benefit from permitted development for any changes however windows and doors are usually the exceptions, but this is at the discretion of your local planning authority. Taking Westminster as an example, if you own a flat or office which is not in a conservation area and you want to replace your old single glazed timber sash windows with new ‘like for like in appearance and material’ timber sash windows then Westminster will not require a planning application. If you wanted to replace your windows with uPVC then Westminster may ask for a planning application to discourage the use of uPVC windows in period housing.
In summary, you are free to change your windows and doors without any formal permissions. It is worth noting that all replacement windows and doors are within the scope of building control regulations. This means that replacement windows or doors must comply with thermal performance and safety standards. If you choose a FENSA registered company to install your new windows or doors then the installer must legally ensure that your new windows conform to building control regulations and certify them with your local authority’s building control office.
Category 2 - Houses which are in a conservation area and are not listed.
The Quick Answer: Planning permission is NOT needed for houses to replace the windows and doors on condition that the new items are ‘like for like in materials and appearance’. Timber must be replaced with timber, and sliding sash with sliding sash.
You do not normally need planning permission to change your windows and doors if your property is a dwelling house (not a flat or office) in a conservation area on condition that they are ‘like for like in material and appearance’. This means if your outgoing windows are made of timber then your new windows must be also made of timber, and if your outgoing windows are sliding sash windows then so must the new ones be.
There is one exception to this, if your property is covered by an Article 4 Direction then you will need planning permission in all instances. The effect of an Article 4 direction is that a planning application is required for developments that would otherwise not require an application for planning permission. In general planning applications for Article 4 properties are only approved when the change of windows is ‘like for like’ in both style and materials.
Category 3 - Flats and offices which are in a conservation area and not listed.
The Quick Answer: Planning permission is NOT needed for flats and offices to replace the windows and doors on condition the new items are ‘like for like in materials and appearance’. However, each local planning authority has a local policy regarding flats and offices and they may insist on a planning application.
Planning law for flats, maisonettes, and offices differs to that which covers houses as they do NOT technically benefit from permitted development and therefore you need planning permission for any changes. However, windows and doors are usually the exceptions to this, but again this depends on your individual local authority. Local authority policy and interpretation of the rules covering changing windows in flats varies from council to council and you are advised to contact your local planning authority for advice before starting work. The majority of local authorities in London and the rest of England have the following policy:
If your property is a flat or an office in a conservation area then you do NOT need to apply for planning permission to change your windows and doors on condition the new items are ‘like for like in material and appearance’. This means if your outgoing windows are made of timber then your new windows must be also made of timber, and if your outgoing windows are sliding sash windows then so must the new ones be.
There is one exception, if your property is covered by an Article 4 Direction then you will need planning permission in all instances. An Article 4 direction is a special planning regulation adopted by a local planning authority. It removes permitted development rights from whatever is specified in the Article 4 direction.
Category 4 - Listed buildings of all grades, both houses, flats and offices.
The Quick Answer: Yes, planning is needed in every instance.
If you live in a listed building you will need planning permission and listed building consent to change your windows and doors. The rules around replacing windows and doors in listed buildings are strict and for good reason, as they are designed to protect our architectural heritage. In general, it is very difficult to get planning permission, in fact, it’s easier to list the reasons why planning can be refused rather than granted:
- You will not get permission to change your windows unless they are beyond economical repair, for example, if the sash box is completely rotten. Reasons such as “they are old, single glazed, or they let out loads of heat” are not valid reasons. The planners will want you to repair and maintain historical windows so you must demonstrate that this is not possible.
- You will not get permission to change from single to double glazing. However, special heritage ‘slimline’ double glazing is usually acceptable in Grade 2 buildings. With Grade 2* and Grade 1 properties is very difficult to get permission to use slimline glazing, usually only single glazing is acceptable. In addition, your conservation officer may insist on traditional ‘hand-drawn’ glazing, this glass is handmade and has ripples and imperfections in it.
- You will not be allowed to change materials, such as timber to uPVC or the appearance of the windows or doors.
In general planning permission to replace your windows and doors is usually only granted in listed buildings when the existing windows and doors are beyond economical repair, the new items have heritage appropriate glazing, and the new items are identical in appearance.
Can I use double glazing in my period property which is listed?
The answer to this question depends on various factors, such as your listing type, your local authority, and whether your windows and doors are historic or not.
Grade 1 and 2* listed buildings typically cannot use any form of double glazing, nor replace windows that have historical significance, such as those that are original to the property’s construction. While the same restriction typically applies to Grade 2 listed buildings, they may be permitted to use 18mm or 24mm double glazing in some cases. However, it is usually preferable to use heritage-appropriate glazing like slimline 12mm double glazing or single glazing. If windows are out of public view, such as those on the back of a house, you may obtain permission for area double glazing. Ultimately, your local conservation officer will decide which type of glazing is appropriate, so it is advisable to meet with them before submitting a full application to discuss their preferences. The preservation of historic windows and avoiding any “harm” from changes are taken into account, and each planning officer has their own interpretation of what constitutes harm. In summary, replacing windows in a listed building can be challenging, if not impossible.
We’re very proud in being a timber only company, helping to preserve London’s architectural heritage. If you have any questions about your options we are happy to help, over the phone on 020 3198 4472 or via email email@example.com
Did you know we also offer planning services, check out our page
Planning permission services to change windows and doors
for more details.