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Energy efficiency guidance for householders

Get advice on whether planning permission is required for common retrofit measures.

Replacing or upgrading your windows

It is possible to make your windows more energy efficient through draught-proofing, adding secondary glazing or incorporating thermally efficient, double or triple glazing, where appropriate. Secondary glazing or draught-proofing will not require planning permission but you may need to make an application for new windows in some circumstances summarised below.


For most houses (for example, where the whole building is in use as one house) you can replace existing windows (or create new windows) without making an application. You only need to apply for householder planning permission for changes to a window or installation of new windows if:

  • they will not be constructed with materials of a similar appearance to the existing windows
  • your house has had its permitted development rights removed – this may be the case if your house is in a conservation area covered by an Article 4 Direction or if they have been removed by a condition attached to an earlier planning permission. Search our planning records.
  • you are creating a new window(s) which would be located on an upper floor of the side of your house (including the roof slope) and would be clear-glazed and openable 
  • for windows in the side elevation of a house on the upper floors to be permitted, they must be obscure glazed and may only be openable if the openable part of the window is more than 1.7m above the floor of the room in which it is installed.


Flats and other buildings do not have permitted development rights and planning permission is normally required for replacement windows. Please apply via our website for full planning permission.

Listed Buildings

In addition to the above, if your house or flat is a listed building, or within the curtilage (garden or grounds) of a listed building, you must apply for listed building consent for new windows, alterations to your windows or secondary glazing. 


Read more detailed information and guidance in our retrofit how to guide on how to upgrade your windows to improve their energy efficiency.

To protect the character of the building and area, we recommend any replacement windows should follow the style of the original windows and replicate the appearance, materials, detailing and opening type.

Replacement windows generally have to comply with thermal insulation standards set out in building regulations, see our building control pages for further information. However, there are exemptions for heritage assets.

If you want to change windows in a listed building or conservation area, read our retrofit guide and follow Historic England's advice on modifying historic windows as part of retrofitting energy-saving measures.

Published: 13 April 2022

Last updated: 10 January 2023