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Do Replacement Windows Need Planning Permission?

 

Replacement windows in a house can normally be installed under permitted development rights, provided they have a similar appearance to the windows previously used in the property.

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This means that straightforward replacement is unlikely to require planning permission where the new windows retain broadly similar:

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• Dimensions and proportions

• Frame appearance

• Opening arrangements

• Glazing patterns

• Position within the existing openings

• Overall external appearance

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Repairs and maintenance, including replacing broken glass or repairing frames, handles and hinges, will not usually require planning permission.

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Internal secondary glazing can also normally be installed without making a planning application.

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When Do You Need Planning Permission to Change Windows?

 

Planning permission may be needed where the proposed work significantly changes the external appearance of the building.

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Examples can include:

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• Enlarging an existing window opening

• Reducing the size of an opening

• Changing traditional sash windows to a different style

• Replacing timber frames with a materially different design

• Altering the glazing-bar arrangement

• Installing windows in a new position

• Creating a new bay window

• Changing several windows in a way that affects the main elevation

• Installing windows where permitted development rights have been removed

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The importance of the change will depend on its visibility and effect on the character of the building.

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Alterations to windows on the front or principal elevation are generally more sensitive than changes to windows at the rear.

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Planning Permission for a New Window

 

A completely new window can often be added to a house without planning permission where it has a similar appearance to the existing windows.

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However, particular rules apply to a new window in an upper-floor side elevation. It will normally need to be:

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• Obscure glazed; and

• Non-opening below 1.7 metres above the internal floor level

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These restrictions are intended to protect the privacy of neighbouring properties.

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Planning permission for a new window may be required where it does not meet the permitted development conditions, creates unacceptable overlooking or substantially changes the external appearance of the property.

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Enlarging an Existing Window

 

Making an existing window wider or taller is more likely to require planning consideration than installing a direct replacement.

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A modest change to a rear window in a house may sometimes be permitted development. A substantial alteration to a prominent front window could require a planning application, particularly where it changes the proportions or character of the elevation.

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Structural work may also be required when enlarging an opening. The lintel and surrounding wall will need to be assessed to ensure that the altered opening is adequately supported.

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New and Replacement Bay Windows

 

Replacing the windows fitted within an existing bay will normally be treated in the same way as other replacement windows, provided the overall bay structure is retained and the new frames have a similar appearance.

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Creating a completely new bay window is different. A bay projects beyond the original wall of the house and is therefore treated as an extension. A new bay on the front of a property is likely to require planning permission.

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Windows in Flats and Maisonettes

 

Flats and maisonettes do not benefit from the same householder permitted development rights as single-family houses.

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A genuinely identical, like-for-like replacement may not always require planning permission. However, permission is more likely to be needed where the new windows differ in:

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• Material

• Colour

• Frame thickness

• Opening style

• Glazing pattern

• Overall external appearance

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Leaseholders may also need permission from the freeholder or managing agent, even where a planning application is not required.

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Because the rules for flats can depend on the nature of the proposed change and local planning policy, the position should be confirmed with the local authority before ordering the windows.

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Windows in Conservation Areas

 

Being located in a conservation area does not automatically mean that every window replacement requires planning permission.

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A house may still retain permitted development rights, particularly where the proposed windows have a similar appearance to the existing ones. However, councils pay close attention to window materials, proportions and detailing because windows can make an important contribution to the character of a conservation area.

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Planning permission may be required where:

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• An Article 4 Direction applies

• Permitted development rights have been removed

• Traditional windows are being replaced with a noticeably different design

• The property is a flat

• The alterations affect a prominent elevation

• The proposed frames do not preserve the character of the building

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The council’s conservation area guidance and Article 4 Direction should be checked before replacing the windows.

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Listed Buildings

 

Listed buildings are subject to separate controls.

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Listed building consent will normally be required where replacing or altering windows would affect the building’s special architectural or historic character. This can include replacing original frames, changing the glass, introducing double glazing or altering the opening mechanism.

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The preferred approach is generally to repair historic windows where practical. Where replacement is justified, the council may expect the new windows to reproduce the materials, profiles, proportions and details of the originals.

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A property can be both listed and located within a conservation area. In that situation, listed building consent and planning permission may both need to be considered.

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Article 4 Directions

 

An Article 4 Direction allows a local authority to remove specific permitted development rights from properties in a defined area.

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Where an Article 4 Direction controls window alterations, changing windows that would ordinarily be permitted development may require planning permission.

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Article 4 controls frequently apply to windows facing a road or other public area. Their purpose is to prevent the gradual loss of traditional features that contribute to the character of the neighbourhood.

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The council’s planning website should identify whether an Article 4 Direction affects the property.

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Elevation Plans and the Planning Application

 

Where permission is required, the application will normally need to include existing and proposed elevation plans showing the affected windows.

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The drawings may need to identify:

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• The location of every window being altered

• Existing and proposed frame arrangements

• Opening styles

• Glazing patterns

• Materials and finishes

• Window dimensions

• Frame and glazing-bar proportions

• The relationship with the surrounding elevation

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Detailed window drawings, sections, photographs or product specifications may also be required for conservation areas and listed buildings.

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Planning approval should be obtained before the existing windows are removed or the replacement windows are manufactured.

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TIP: Visit Draw Plans for a FREE Quote for Elevation Drawings & Planning Application Services

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Building Regulations for Replacement Windows

 

Planning permission and Building Regulations are separate requirements.

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Even where a planning application is unnecessary, replacement windows must still meet the relevant requirements for matters such as:

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• Thermal performance

• Ventilation

• Safety glazing

• Structural support

• Means of escape

• Protection against falling

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An installer registered with an authorised competent person scheme can normally self-certify qualifying replacement window work.

 

Otherwise, an application may need to be made through building control.

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Confirming That Permission Is Not Required

 

Where there is uncertainty, the local planning authority can be asked to confirm whether the proposed work requires permission.

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For formal confirmation, a homeowner may apply for a Lawful Development Certificate. This can provide evidence that the proposed window installation is lawful and may be useful when the property is eventually sold.

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Find Trusted Window Installers

 

Checking the planning position before ordering windows can prevent delays, additional expense and the risk of installing an unacceptable design.

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APN Double Glazing can connect homeowners with experienced local installers for replacement windows, new window openings and specialist glazing projects.

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Where planning permission is required, properly prepared elevation plans and a planning application should be arranged before installation begins.

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Get in touch for expert advice and a free, no-obligation quote for your window project.

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