Do I need planning permission for an extension to my house?
Yes, If any of the following apply...
Building an extension, porch or conservatory onto your house, or an outbuilding or garage less than 5 metres (16ft 6in) from your house (including existing extensions).
a. If the house is a listed building you need planning permission.
With Porches, You do if...
b. The proposed porch has an external floor area of more than 3 square metres. (a 1.2 metre (4 ft) by 2.4 metre (8 ft) porch has a 3 metre square floor area.
c. The porch roof is more than 3 metres (9ft 10in) high.
d. The porch is less than 2 metres (6ft 6in) from the pavement.
GROUND LEVEL EXTENSIONS
e. The house is a terrace or in a conservation area and the extension will mean that the external volume of extensions added to the house will be more than 50 cubic metres. (an extension with a legnth of 3 metres (9ft 10in) width of 5 metres (16ft 6in) and with a three metre (9ft 10in) high flat roof has a volume of 45 cubic metres.
f. The house is a semi detatched or detached house outside a conservation area, and the proposed extension will mean that the external volume of extensions added to the original house will be more than 70 cubic metres.
g. The extension is higher than the roof of the house.
h. The extension is more than 4 metres (13ft 1in) high within 2 metres (6ft 6in) of any of the property boundaries.
i. The extension covers more than half the garden.
j. The extension is closer to the nearest road or footpath than the original house (unless that road or footpath is more than 20 metres (65ft 8in) away.
Loft conversions are covered by the requirements of e. and f. above, as they are extensions to your house. In addition you need planning permission if the following applies;
k. The roof extension is higher than the highest part of the roof.
l. The roof extension faces onto a road or footpath.
m. In a terrace the external volume of the roof extension is more than 40 cubic metres ( this is massive, a roof extension 3 metres (9 ft 10in) long with a 2 metre (6ft 6 in) roof depth and a height of 2 metres (6ft 6in) on the slops of a 45 degree pitched roof only adds a volume of 6 cubic metres).
n. In a semi detached or detached house the volume of the roof extension is more than 50 cubic metres.
o. The house is in a conservation area.
This advice only relates to houses, you ALWAYS require permission for extensions if you live in a maisonette or a flat.
If you dont need planning permission you may require other permissions, including building regulation approval.
OUTBUILDINGS, SHEDS, GARAGES ETC;
Any building in the garden of a house (not a flat or maisonette) that is more than 5 metres (16ft 6in) from the house is considered to be an outbuilding. Planning permission is needed for an outbuilding if;
a. It is closer to the nearest road or footpath than the original house (unless that road or footpath is more than 20 metres (65ft 8in) away.
b. It is more than 4 metres (13ft 1in) high if it has a sloping roof with a ridge, or more than 3 metres (9ft 10in) high if it has any other sort of roof (including flat roofs).
c. It covers more than half the garden area.
d. The house is a listed building, or in a conservation area. If this is the case, any building with an external volume of more than 10 cubic metres needs planning permission.