Depending on the planning constraints on the property and the appearance of the proposed windows, you may or may not need planning from the council to replace the windows in your property.

1. Replacing the windows in a house

Most houses have permitted development rights, which make it possible to replace existing windows (or create new windows) without requiring planning permission from the council, so long as:

  • The materials of the proposed windows must be 'of a similar appearance' to the materials of the existing windows, and
  • Any upper floor side windows must be obscure-glazed and non-opening. (Note that the non-opening requirement does not apply if the parts of the window that can be opened would be more than 1.7m above internal floor level).

If the proposal does not comply with points above then planning permission will be required.

Not all houses have permitted development rights. Sometimes these rights have been removed by a condition attached to a previous planning permission or by an Article 4 Direction.

If permitted development rights have been removed, then planning permission will be required if there are noticeable differences between the existing and proposed windows.

2. Replacing the windows in a flat

Flats do not have permitted development rights for changes to windows. If the design, method of opening, materials and profile of the replacement windows are not the same as the existing windows, then planning permission will normally be required.

If you need to apply for planning permission, then please check that your proposal complies with the following guidelines:

  1. Proposed additional, altered, replaced or enlarged windows and doors should be in keeping with the original design and materials of the original building. This must create a consistent architectural composition, appropriate to the historic character of the area or building.
  2. Building regulations now require replacement windows to meet high thermal efficiency standards. Whilst PVCu windows may meet these requirements, their use will not be acceptable where this would harm the character of the building.

3. Replacing the windows in listed buildings and conservation areas

If the property is on the council’s or national list of buildings of special architectural or historic interest you need to apply for planning permission and listed building consent to replace the windows.

Replacement windows in these instances will be expected to be a very close match to the originals. We therefore advise that you check the policy below before submitting your request for planning permission.

You will need to view policies 46 and 47 for the council’s local list and policy 45 for the statutory national list.

4. Improving windows without need for planning approval

The refurbishment and draught-proofing of existing windows can improve their thermal performance. Similarly, the installation of internal secondary glazing can also significantly improve thermal performance and sound insulation. These works do not require planning permission.

Internal secondary glazing is generally supported on listed buildings but may require listed building consent depending on its impact on the special interest of the building.