Do you need planning permission for windows?

If you're thinking about replacing your windows, you might be wondering if there are any regulations you need to know. Or, if you need planning permission to change windows?

In some instances, you do need planning permission for windows, but just as importantly, there are strict building regulations for glazing that you need to adhere to.

As a reference, we've outlined the standard guidelines that apply when changing your windows. We've also answered the most common question we get asked about changing your windows.

This guide has been updated to include the Building Regulations Part O and Part F 2022.

Do you need planning permission for windows? (Updated for 2023)

If you're simply replacing windows in a similar style and size used on the build of the house, you DON'T need to apply for planning permission.

If you want to add new windows then in some cases you DO need planning permission.

There are guidelines for what falls into permitted development and for when you need planning permission:

Windows

You don't need planning permission to replace doors and windows with those of a similar appearance.

Building regulation approval is required on any glazing replacement work or you can use a registered installer (such as Everest) to complete approved work for you.

You DO need planning permission if:

Fitting a skylight/roof light that protrudes more than 150mm beyond the plane of the roof slope or...
...is higher than the highest point of the roof
Fitting an upper-floor side elevation window that is not obscure-glazed and can open (unless the opening part is 1.7 metres from the floor of the room)

You MAY need permission if you live in a listed building, designated area or fall under an Article 4 Directive.

Planning permission for new windows

Do I need planning permission for a bay window?

Bay windows are a little different to a standard window as they protrude out from the wall of the house. Because of this, for planning permission purposes, they're treated like an extension:

If you're replacing an existing bay window then you DON'T need planning permission
If you're adding new bay windows at the front of the house, you DO need planning permission
If you're adding new bay windows at the side and back of the house usually you DON'T need planning permission

Planning permission for windows

Do you need building regulations for new windows?

Planning permission controls IF you're allowed to build or change a structure. Building regulations control the quality and HOW you build a structure for safety purposes.

In addition to planning permission, you DO need to comply with building regulations for windows.

The main areas that building regulations cover for windows are:

Thermal heat loss - windows are required to meet the minimum standards for the amount of heat they allow to pass through. This is measured as a U-Value.
Safety glazing - in certain areas, safety glazing must be used to protect in case of an accident: for a door with glass up to 1500mm from floor level and for an unobstructed openable area at least 0.33 square metres and 450mm high and 450mm wide.
Ventilation - for rooms such as kitchens and bathrooms with a high production of steam, mechanical fans and window ventilation are needed. For other rooms, standard windows and trickle vents are used.
Fire safety - some external windows may need to be fixed shut to limit the spread of fire between properties.
Means of escape - a replacement window can only be reduced to a size that a person can escape through (or it can be the same size). New windows must follow the criteria set for escape windows (see here).

If you want to read more about building regulations for windows, you can find a list of the most recent approved documents for building regulations here.

Instead of seeking approval for building regulations yourself, you have the option to use a registered installer (such as Everest) who are approved to carry out window replacement work.

The supplier will give you a certificate that shows the work was completed by a registered supplier and that the windows meet building regulations.

Building regulations Part O, reducing overheating in buildings

Prompted by climate change, additions to building regulations came into effect in June 2022.

As part of a drive towards reducing emissions, the regulations are intended to reduce overheating in houses by:

Limiting unwanted solar gains in summer
Providing adequate means of removing excess heat from a building

Part O relates to glazed areas of new build properties

Windows and glazed areas will be limited to a maximum size depending on:

The floor area of the room
The direction they face (south, north, east, west)
If the building is in a high-risk area (London postcodes being the highest risk)
Cross-ventilation inside the building (opening windows on opposite facing walls).

In high-risk areas, the use of external shading will be required. Internal blinds and curtains and tree foliage cannot be used for shading.

We recommend reading the documentation of Part O for full guidelines.

Part F relates to replacement windows in existing buildings

If the windows to be replaced currently have background (trickle) ventilators, then the replacement windows must have vents of at least the same size.

If the windows to be replaced don’t currently have background ventilators, then it must be shown that the ventilation will be made no worse than it was before the windows are changed. This may include having background ventilators fitted to the new windows.

It might be considered that a trickle vent could reduce the energy efficiency of the window, but this is not the case. Trickle vents can be closed so that the window frame is still air tight and draught-proof.

Vents are essential so that air can circulate in a room and remove any moisture in the air. This reduces condensation, mould and dampness which can be an issue in modern homes if they are not ventilated on a regular basis.

We recommend reading the documentation of Part F for full guidelines.

Planning permission for windows

Do I need planning permission to paint my windows?

If you want to paint your windows a different colour then you DON'T need planning permission or building regulations.

However, depending on the property you live in, there may be restrictions to what you can do to the external appearance. For example, in listed buildings or for leaseholders.

Restrictions that you need to check before painting or replacing windows:

Listed buildings

You need listed building consent before replacing windows and you'll be restricted to the style and colour of your windows and frames.

Designated areas

Conservation Areas, National Parks, Areas of Outstanding Natural Beauty and World Heritage Sites have restrictions similar to listed buildings and you'll need to seek approval from the relevant authority before replacing any windows.

Article 4 Direction

Check that your local council doesn't have a directive in place that overrides permitted development rights.

Leaseholder

For leasehold properties such as apartments and new build developments, there may be covenants in the lease that restrict the style and colour of windows you can have. Before making any changes to your windows (including painting a different colour) contact the management company for permission.

More information

Read a more detailed explanation on the technicalities of permitted development rights for householders here.
Read more information about building regulations here.
The information provided above is taken from government guidelines at from the Planning Portal and Gov.uk and is a guide only and is not a source of legal information.

Information is correct at time of publication: Updated January 2023.

Planning rules are subject to change. Always seek approval from your local planning authority before starting any building work.