Roofs and Porches
Roof extensions
Planning permission may not be required providing:
The Enlargement of a dwelling house consisting of an
addition or alteration to its roof.
In order for a development to be PD the development must
comply with the following:
- A volume allowance of 40 cubic metres for terraced houses
- A volume allowance of 50 cubic metres for detached and
semi-detached houses.
- No extension beyond the plane of the existing roof slope of the
principal elevation that fronts the highway.
- No extension to be higher than the highest part of the
roof.
- Roof extensions not to be permitted development in designated
areas*.
If a development is considered to be PD under class B
the following conditions must be applied:
- Materials to be similar in appearance to the existing
house.
- No verandas, balconies or raised platforms.
- Side-facing windows to be obscure-glazed; any opening to
be 1.7m above the floor.
- Roof extensions, apart from hip to gable ones, to be set
back, as far as practicable, at least 20cm from the eaves.
Any other alterations to the roof of a dwelling
house
- In order for a development to be PD the development must comply
with the following:
- Any alteration to project no more than 150 millimetres from the
existing roof plane.
- No alteration to be higher than the highest part of the
roof.
- Side facing windows to be obscure-glazed; any opening to be
1.7m above the floor.
Porches
Planning permission may not be required
providing:
- The ground floor area (measured externally) would not exceed
three square metres.
- Any part would not be more than three metres above ground level
(height needs to be measured in the same way as for a house
extension).
- Any part of the porch would be within two metres of any
boundary of the dwelling house and the highway.
Note: This is unchanged from previous GPDO
This webpage was updated on
10/2/2008