The Government intend to bring into force amendments to householder permitted development rights, including those for roof extensions, in October this year. The proposed regime will keep the current approach that allows householders roof extensions of up to no more than 40 cubic metres for terraced houses and 50 cubic metres for detached and semi-detached properties. An extension will not be permitted on a roof that fronts the house and is visible from the highway. Rear loft extensions will have to be set back at least 20 centimetres from the eaves.
A key change for all types of household extension is that the overall household volume restriction will be removed. This means that householders will no longer have to apply for planning permission for loft extensions if they have already extended at ground level.
Roof extensions will not be permitted development in certain sensitive areas such as conservation areas and national parks.