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Applications under building regulations Children

Extension

An extension to a house does not require an application for planning permission provided that:

Size and position

The floor area of the extension does not exceed 20 square metres
No part of the extension will extend forward of any elevation of the house that faces a highway

Conservation area/constructed before 1900

Where the house is within a conservation area or is substantially constructed before 1900, the extension does not have a flat roof and is not located on an elevation of the house that is visible from a highway
Where the house is not within a conservation area, is not substantially constructed before 1900 and the extension has a flat roof, the extension is located on an elevation of the property that is not visible from a highway

Roof and height

Where the extension does not have a flat roof, the roof is a lean to or a double-pitched roof with, in both cases, a pitch of not less than 22 and a half degrees
The height of any elevation of the extension, where it meets the eaves of the roof of that extension, does not exceed 3 metres and height of the roof of the extension, measured to the apex of that roof where that roof is pitched, does not exceed 4 metres
Where any part of the extension is within 1 metre of any boundary with a neighbouring property, the height of that part does not exceed 2 metres

Other criteria

Glazing is not included within any elevation which is located within 1 metre of a boundary with a neighbouring property
The extension is attached to the external walls of the house as it was originally constructed
The walls, other than glazed areas, are constructed of the same material as the predominant material used in the construction of the walls of the house
The roof, other that glazed areas, is covered in a material to match the predominant material used in the existing roof of the house
Any opening designed to admit a motor vehicle is set back at least at least 5 metres from a highway accessible from that opening
The house including the extension to be erected is not within a site of special significance

This exemption does not apply to a Protected Monument or Protected Building.

This work is not exempt under building regulations and an application for a licence under the building regulations may be required.

Download the full exemption information sheet (including diagrams) from the downloads section