Replacement double and triple glazing windows

Free planning advice is available for residents if you are considering replacement windows or other energy efficiency measures via our Duty Planning Service

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Illustration of a thermal insulation plastic window frame profile isolated on white background. Cross-section diagram of a double glazed window pane UPVC profile reflecting cold and heat.

Energy efficient glazing covers both double and triple glazing. These are windows with two or more glass panes in a sealed unit.

Having energy efficient windows could help to reduce your carbon footprint and your energy bills.

Planning permission

Single dwelling houses

The installation of replacement windows to a single dwelling house does not generally need planning permission, except where a change of window frame material is proposed (e.g. timber to PVCu and vice versa).

If your single dwelling house is covered by an Article 4 Direction that removes permitted development rights for external alterations then planning permission for replacement windows may be required. More information is available here: Properties affected by Article 4 Directions

If your single dwelling house is a listed building, then planning permission would be required for the installation of replacement windows. Listed Building Consent would also be required for the installation of replacement windows and any internal works such as the installation of secondary glazing.

However, to respect the character of the building and local area, we recommend any replacement windows should follow the style of the original windows and replicate the appearance, materials, frame/glazing detailing, and opening type, where achievable.

Flats and maisonettes

The installation of replacement windows to a flat or maisonette does not require planning permission so long as the replacement windows are identical 'like-for-like' replacements in terms of appearance and material.

Planning permission is likely to be required, if the replacement windows would not match the appearance and material of the existing windows in terms of:

  • material (such as timber to PVCu and vice versa)
  • subdivision and thickness of the window frame and glazing bars
  • size of window openings.

You will not usually need planning permission to add internal secondary glazing.

If your flat or maisonette is located within a listed building, then planning permission would be required for the installation of replacement windows.

Listed Building Consent would also be required for the installation of replacement windows and any internal works such as the installation of secondary glazing.

Listed buildings

More information about listed buildings is available here: Statutory Listed Buildings.

Separately, if the property is a flat or maisonette you may need the freeholder's permission to make changes to exterior of the building depending on the terms of your lease.

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