Guidance for making a windows planning application
If you need planning permission or listed building consent, then we recommend you follow the guidance below to prevent your application being delayed or refused.
Replacement windows should match the originals
In order to protect the character of the building, replacement windows should match the appearance, detailing and opening type of the originals.
This is particularly important where windows share the same design across a group of buildings or flats.
For listed buildings and in conservation areas, known as 'heritage assets' if you don't accurately reproduce the originals then permission is likely to be refused.
Thermal insulation standards
Replacement windows generally need to meet thermal insulation standards as set out in building regulations.
To meet these standards new windows will usually need to be double glazed, although exemptions from the building regulations are available on heritage assets to make sure new work doesn't harm the special interest of the building.
Window design
As a general rule replacement windows should:
- fit neatly into existing openings, recessed into the established reveal depth
- avoid stick-on or non-integral glazing bars as they can loosen and fall off.
On heritage assets replacement windows should:
- avoid visually obvious trickle-vents
- be of the same material as the original windows.
The Planning Portal also has guidance on planning and building regulations.
Scale drawing requirements
Please provide drawings of the original and proposed windows so that we can easily compare them.
Listed buildings and properties in Article 4 Direction areas
Please provide 1:20 scale elevations and larger scale 1:5 or 1:2 detailed cross sections.
Cross sections should show how the window unit sits within the window reveal and relates to the existing sill.
For sash windows, section drawings should include top rail (including sash box), glazing bar, meeting rail (of both sashes), bottom rail, sill (including sash box).
If your building is listed, you'll also need to provide a condition report of the existing window along with the listed building consent application.