Enlarging a Dwellinghouse

It is important to understand the definition of enlargement. Enlargement is defined as any development that increases the internal volume of the original dwellinghouse and includes a canopy or roof, with or without walls, which is attached to the dwellinghouse, but does not include a balcony. Therefore, a car port is an enlargement but a balcony is not.

There are many types of enlargements and the following 4 classes cover the most common types.

 

Single storey ground floor extensions

Enlarging Single storyThis is the most popular type of enlargement. This class permits a single storey extension to be built in the rear garden. The height of the eaves of the extension cannot be higher than 3 metres and the overall height of the extension cannot be higher than 4 metres.

If the extension is within a metre of a boundary it cannot extend from the rear wall of the existing house for more than 3 metres in the case of a terraced house or 4 metres in other cases. The area covered by any existing and proposed extension cannot be greater than the area of the original house or 50% of the area of the curtilage.

There are no permitted development rights for single storey ground floor extensions in conservation areas or for flats. Listed building consent will normally be required if your building is Listed.

A building warrant from the local authority will likely be required for this type of extension.

For more information on the limitations for this class please see the Circular

Ground floor extensions of more than one storeyGround floor extensions of more than one storey

This class covers extensions that contain more than one floor. Most typically, this would be either a 1½ storey extension or a 2 storey extension.

Many 1½ storey and 2 storey extensions are more likely to have a greater impact than a single storey extension.  The extension must be at least 10 metres from any boundary. Most extensions will not be able to meet this criterion, therefore an application for planning permission would be required.

There are no permitted development rights in conservation areas or for flats. Listed building consent will normally be required if your building is Listed.

A building warrant from the local authority will likely be required for this type of extension

For more information on the limitations for this class please see the Circular.

 

PorchPorch

This class permits the construction of a porch on any external door of the dwellinghouse.  The porch cannot be higher than 3 metres.  The overall footprint of the porch cannot be more than 3 square metres.

The minimum distance between the porch and any boundary and a road is more than 2 metres

There are no permitted development rights for porches in conservation areas or for flats. Listed building consent will normally be required if your building is Listed.

A building warrant from the local authority may be required for a porch.

For more information on the limitations applying to this class please see the Circular.

 

Enlargements of the roof

Enlargements of the roofThis class typically relates to a dormer extension on a roof. 

A badly designed dormer can harm the appearance of a dwellinghouse. The larger the dormer, the more challenging it is to produce a good design.

The width of the dormer must less than half of the width of the roof plane, and it must be at least 30cm from any edge of the roof. A dormer must be at least 10 metres from any boundary that it faces. It cannot be on any principal elevation or side elevation that fronts a road.

There are no permitted development rights for roof enlargements in conservation areas or for flats. Listed building consent  is required if the proposed development affects the character or setting of a listed building.

A building warrant from the local authority will be required for this type of extension.

For more information on the limitations applying to this class please see the Circular.