You can extend a detached dwelling by 8m to the rear if it s single storey or 3m if it s double.
Permitted development flat roof extension.
Areas where there may be a planning condition article 4 direction or other restriction that limits or removes permitted development rights.
Materials to be similar in appearance to the existing house.
You do not normally need to apply for planning permission to re roof your house or to insert roof lights or skylights as the permitted development rules allow for roof alterations subject to the following limits and conditions.
Gaining permitted development rights for extensions means that you can avoid having to apply for planning permission so will need slightly less paperwork and will make a slight cost saving.
An extension beyond the plane of the existing roof slope of the principal elevation that fronts a highway is not permitted development.
No part of the extension to be higher than the highest part of the existing roof.
Any alteration to project no more than 150 millimetres from the existing roof plane.
The roof enlargement cannot overhang the outer face of the wall of the original house.
If the extension is within 2m of a boundary maximum eaves height should be no higher than 3m to be permitted development.
So long as the eaves height of the flat roof is only 3m.
Side extensions to have a maximum height of four metres and width no more than half that of the original house.
Width of side extension must not have a width greater than half the width of the original house.
See below for a detailed guide to permitted development rules for single and double storey rear extensions side and roof extensions loft conversions porches and outbuildings.
The new permitted development legislation 2008 is full of.
Roof extensions not on article 2 3 land conservation area aonb broads.
I m wondering if a flat roof extension to a pitched roof bungalow is permitted development the depth of the extension would be 3m and the height would not exceed 3m my slight concern would be about matching materials as the existing pitch roof is concrete tiles and the flat roof would be a single ply membrane.
It should also speed up the whole process a little.
Extensions cannot be higher than the highest part of the existing roof.
If you can prove by technical analysis that the roof pitch of the extension was the best you could practically achieve then you should be safe but have your technical explanation on the pitch difference ready and tested.
Verandas balconies or raised platforms are not.
Semi detached and terraced homes can be extended up to 6m to the rear of the property if single.
Extending under permitted development rights is entirely possible to do under the current rules.
So while permitted development rights are beneficial there s a lot to consider before starting work.
Permitted development rules for extensions.