Planning circular 1/2024: householder permitted development rights

7. Altering or replacing existing windows

General information

7.1 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.

7.2 Even where the alteration or replacement of an existing window (or windows) would affect a building’s external appearance, planning permission is in most cases granted by PDR under Class 7A of the GPDO. These PDR (reproduced in full below) apply to both domestic and non-domestic properties.

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

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

7.5 Planning permission and listed building consent are separate approval processes. Irrespective of whether planning permission is needed, listed building consent will need to be obtained if a building is listed. Planning authorities will be able to confirm whether a property is located in a conservation area. Historic Environment Scotland’s website has information about listed buildings.

Altering or replacing existing windows in a conservation area

Summary

7.6 Class 7A PDR apply in conservation areas. However, if your house or flat is in a conservation area you may need to notify the planning authority and submit some additional information before altering or replacing a window; the authority then has an opportunity to consider the acceptability of the proposal. This process is described below (paragraphs 7.12 – 7.17). Whether you need to notify the planning authority will depend on:

• Where the window(s) you intend to replace are situated on the building.
• The design of the proposed replacement and how it compares to the design of the existing window.

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

7.7 For windows on the rear elevation of a building in a conservation area, there are no restrictions on the design or appearance of the replacement/altered window – and you will not need to submit any additional information to the planning authority. This is also the case for windows on the side elevation of the building - unless that side elevation fronts a road.

7.8 See section 3 of this document for guidance on how to identify the rear, side and principal elevations - as well as what is meant by ‘fronting a road’.

Window on the front of a property (or a side fronting a road) in a conservation area

7.9 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 your proposal (before carrying out the works) and submit some additional information so that they can take a view on whether the design is acceptable. This process is called “prior notification/prior approval” – sometimes referred to simply as “prior approval” – and is described below.

7.10 You will not need to notify the planning authority and 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.

7.11 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 your planning authority before starting work.

Prior notification/prior approval process

7.12 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 7.10, you will need to notify the planning authority and submit some additional information to them before carrying out the works. This enables the authority to consider whether their prior approval is required in relation to the design and external appearance of your proposal.

7.13 In this scenario, you must send the planning authority:

• A plan indicating the location of your property.
• A written description of your proposal and the materials to be used.
• The relevant fee (£100)^[1]

7.14 An application form is available at ePlanning Scotland together with some additional guidance notes on how to complete the form.

7.15 Upon receipt of the required information (paragraph 7.13), the planning authority has 28 days to indicate whether or not its prior approval is needed. If you do not hear from the authority within that period, you can proceed with the proposed window alteration or replacement. If the authority respond indicating that prior approval is required, you cannot go ahead with the works until that approval is given. The authority’s consideration is limited to the design and external appearance of the proposed window. Statutory neighbour notification and publicity requirements do not apply. In this sense, it is a narrower and lighter-touch process than a planning application.

7.16 It may help the planning authority to reach a view on your proposal if you submit information that goes beyond the minimum set out at paragraph 7.13, for example, photographs of the existing window.

7.17 Unless subsequently agreed in writing by the planning authority, the works must be carried out in accordance with the details approved by the planning authority. In circumstances where the planning authority confirmed that their prior approval was not required, the development must be carried out in line with the details submitted. The work must be carried out within 3 years of receipt of the planning authority receiving the application for prior approval or 3 years from the date on which approval was given.

Legislation

Class 7A

(1) Any alteration or replacement of an existing window^[2].

(2) Development is not permitted by this class within a World Heritage Site.

(3) Paragraph (4) applies to development to alter or replace a window in a conservation area where—

(a)the window is part of—

(i)the principal elevation, or

(ii)a side elevation where that elevation fronts a road, and

(b)the window as altered or replaced would not be the same, or substantially the same, as the window to be altered or replaced in the following respects—

(i)the manner in which the window is opened and closed,

(ii)the number, orientation and colour of the panes comprised in the window,

(iii)the dimensions and colour of the frame of the window or any astragal bars comprised in the window.

(4) Development to which this paragraph applies is permitted by this class subject to the following conditions—

(a)the developer must, before beginning the development, apply to the planning authority for a determination as to whether the prior approval of the authority will be required in respect of the design and external appearance of the proposed alteration to or replacement window,

(b)the application is to be accompanied by a written description of the proposed development, the materials to be used and a plan indicating the site together with any fee required to be paid,

(c)the development is not to be commenced before the occurrence of one of the following—

(i)the receipt by the applicant from the planning authority of a written notice of their determination that such prior approval is not required,

(ii)where the planning authority gives the applicant notice within 28 days following the date of receiving the application of their determination that such prior approval is required, the giving of such approval,

(iii)the expiry of 28 days following the date on which the application was received by the planning authority without the planning authority making any determination as to whether such approval is required or notifying the applicant of their determination,

(d)the development must, except to the extent that the planning authority otherwise agree in writing, be carried out—

(i)where prior approval is required, in accordance with the details approved, or

(ii)where prior approval is not required, in accordance with the details submitted with the application, and

(e)the development is to be carried out—

(i)where approval has been given by the planning authority, within a period of 3 years from the date on which approval was given,

(ii)in any other case, within a period of 3 years from the date on which the planning authority were given the information referred to in paragraph (3)(b).

(5) In this class—

“principal elevation” means the elevation of the building which by virtue of its design or setting, or both, is the principal elevation,

“rear elevation” means the elevation of the building that is opposite its principal elevation,

“side elevation” means the elevation of the building linking the principal elevation with the rear elevation.