Planning circular 2/2024: non-domestic permitted development rights

Annex M: Alteration/replacement of existing windows (non-domestic)

General information

1. Under planning legislation (the Town and Country Planning (Scotland) Act 1997), planning permission is required to carry out “development”. The same legislation says that works which do not materially affect the external appearance of a building do not constitute development for the purposes of planning. As such, the installation of like-for-like windows will not require an application for planning permission. This is the case in all locations.

2. Even where the alteration or replacement of a window (or windows) would affect a building’s external appearance, planning permission is in most cases granted by permitted development rights (PDR) under Class 7A of the Town and Country Planning (General Permitted Development) (Scotland) Order 1992 – also known as “the GPDO”. These PDR apply to both non-domestic and domestic properties.

3. The effect of Class 7A PDR is that in most locations, an application for planning permission is not required to alter or replace an existing window. Some additional rules, which are explained below, apply in conservation areas. There are no PDR for replacement windows in a World Heritage Site.

4. Class 7A PDR do not apply to the creation of new windows in an existing building.

Altering or replacing windows in a conservation area

Summary

5. Class 7A PDR apply in conservation areas. However, if the building is in a conservation area you may need to notify the planning authority and submit some additional information (please see Annex A and paragraphs 10-12 below on prior approval) before altering or replacing a window; the authority then has an opportunity to consider the acceptability of the proposal. This will depend on:

• where the window(s) to be altered or replaced is situated on the building;
• the design of the proposed alteration or replacement and how it compares to the design of the existing window.

Elevation

6. The term “principal elevation” is used to identify the front of the building. The “rear elevation” is the elevation opposite the principal elevation. “Side elevations” link the principal and rear elevation. The “fronting a road” is a way of determining if the side elevation is in the public domain.

Window on the back of a building in a conservation area (or side of building which does not front a road

7. For windows on the rear elevation of a building or on side elevation of the building not fronting a road, there are no restrictions on the design or appearance of the replacement/altered window.

Window on the front of a property or on side elevation which fronts a road

8. Additional restrictions apply to windows situated on the principal elevation of a building and side elevations that front a road. This is because these are generally the more prominent parts of the building and therefore more sensitive to change. Depending on how similar the proposed window is to the existing one, you may need to notify the planning authority of the proposal (before the works are carried out) and submit some additional information so that they can take a view on whether the design is acceptable (please see Annex A and paragraph 10 below for more information) You will not need to submit additional information if the proposed window matches (i.e. is the same or substantially the same as) the existing window as regards:

• Opening mechanism (e.g. sash and case).
• The number, orientation and colour of panes within the window (e.g. six-over-six configuration).
• The dimensions and colour of the window’s frame and any astragal bars.

9. The material of the proposed and existing windows do not need to match. So if, for example, the proposed window would be the same or substantially the same as the existing one in respect of the three criteria above but the proposed window is made of a different material to the existing window, the process described below does not apply. If, however, you propose to replace existing windows with a different material and the replacement would not be the same/substantially the same as the existing one in respect of the three criteria (e.g. width of the frame) then the process below would apply. It is always advisable to check with the planning authority before starting work.

Prior approval process

10. If you intend to alter or replace a window which is: a) on a building in a conservation area; b) situated on the building’s principal elevation (or side elevation that fronts a road); and c) not the same, or substantially the same, as the existing window in relation to the three criteria at paragraph 8, you will need to submit additional information to the planning authority before carrying out the works.

11. In this scenario, you must send the planning authority:

• a plan indicating the location of the property;
• a written description of the proposal and the materials to be used; and
• the relevant fee.

12. It may help the planning authority to reach a view on the proposal if you submit information that goes beyond the minimum set out at paragraph 11. For example, photographs of the existing window.