extension and planning permission

Dobie

Hi All,

Can anyone confirm that I would not need planning permission to construct a 400 sq ft extension to the rear of an existing dwelling.

Thanks

sydthebeat

Small scale domestic extensions, including conservatories, do not require planning permission if the extension is to
the rear of the house and

* for terraced or semi-detached houses, the floor area of any extension above ground level does not exceed 12
square metres, this includes any previous extensions carried out;

* the original floor area of the house is not increased by more than 40 square metres. It is important to note that
where the house has been extended before, the floor area of the extension you are now proposing and the floor area
of any previous extension, including those for which you got planning permission, cannot exceed 40 square metres;

*any extension above ground level is at least 2m from any boundary;

*any extension does not reduce the area of private open space, reserved for the occupants of the house, to less than
25 square metres.


There are also rules about the height allowed in such an extension. These are that -
* if the rear wall of the house does not include a gable, the height of the walls of the extension must not exceed the
height of the rear wall of the house.

* if the rear wall of the existing house has a gable, the walls of the extension (excluding any gable being built as part
of the extension) shall not be higher than the side walls of the house;

* in the case of a flat roofed extension, the height of the highest part of the roof may not exceed the height of the
eaves or parapet. In any other case, no part of the new roof may exceed the highest part of the roof of the house;

* a gable is the upper part of a wall (normally triangular), between the sloping ends of a pitched roof.


There are also rules about the required distances between windows in extensions and the facing boundary of the
adjoining property and the use of the roof of the extension. These are that
*any extension proposed at ground level as part of an extension should not be less than 1 metre from the boundary
they face.
* any windows proposed at above ground level should be not less than 11 metres from the boundary they face;
* the roof of any such extension should not be used as a balcony or roof garden.

muffler

Cheers Syd. That has more than covered everything.

If the OP wants to see it in a semi official version then leaflet PL5 from the DoE also gives a brief summary.

tsquare

Hi, does the 11m rule for windows above ground floor include velux windows or are they considered rooflights? Thanks

sydthebeat

tsquare wrote: »

Hi, does the 11m rule for windows above ground floor include velux windows or are they considered rooflights? Thanks

thats a good question.

In the case of a dormer roof, when the rooflight is the window, then it needs to be in excess of 11m to protect the private amenity of adjoining dwellings.
When the rooflight isnt a window but actually a rooflight, say in the case of a two storey where its tunneled down into a room, then the 11 m wouldnt apply as no overlooking can occur. But in this case the habitable room still needs to comply with fire regs.

muffler

Agreed ^^

RKQ

sydthebeat wrote: »

It needs to be in excess of 11m to protect the private amenity of adjoining dwellings.
The habitable room still needs to comply with fire regs.

I agree, any velux that is a fire escape will most likely overlook neighbours and therefore needs to be in excees of 11m.
Might be best to apply for permission for an extension.