Permitted Development 2012 Consultation

Town and Country Planning Acts Permitted Development 2012 Consultation:

Changes to the 2008 Act

Most houses, detached, semi-detached and terraced have the right to extend or alter the property without the need to apply to the Local Council for Planning Consent. These are known as Permitted Development Rights and are set out in the Planning Acts. The Government is currently reviewing, by way of a consultation, two aspects relating only to the size in terms of length from the rear of a dwelling and then only for a period of three years. It is important to recognise that these proposed changes are not yet implemented in legislation.

Residents in the Welwyn Garden City Estate Management Scheme area should specifically refer to Note 4 below.

For the sake of clarity the current Permitted Development Rights are as follows :-

Under regulations that came into effect on 1 October 2008 an extension or addition to a residential property is considered to be ‘permitted development’, therefore not requiring an application for planning permission, subject to the following conditions and limits :

1.   No more than 50% area of the land around the original house would be covered by extensions, additions or other buildings. (Refer to Note 1 below)

2.   No extension forward of the principal elevation or side elevation fronting a highway.

3.   No extension to be higher than the highest part of the existing roof.

4.   Maximum depth of a single-storey rear extension of three metres for an attached (semi or terraced) house and four metres for a detached house.

5.   Maximum height of a single-storey rear extension of four metres. (The ridge on a pitched roof)

6.   Maximum depth of a rear extension of more than one storey of three metres including ground floor.

7.   Maximum eaves height of an extension within two metres of the boundary of three metres. ( The eaves to a ridged roof or fascia on a flat Roof)

8.   Maximum eaves and ridge heights of an extension no higher than existing house.

9.   Side extensions to be single storey with maximum height of four metres and a width no more than half that of the original house.

10.  Two-storey extensions to be no closer than seven metres to rear boundary.

11.  Roof pitch of extensions higher than one storey is to match the existing house.

12.  Materials to be similar in appearance to the existing house.

13.  No verandas, balconies or raised platforms.

14.  Upper-floor, side-facing windows to be obscure-glazed; any opening to be at least 1.7m above the floor.

13.  No permitted development for rear extensions of more than one storey on designated land.

14.  No cladding of the exterior elevations on designated land.

15.  No side extensions to dwellings on designated land.

The new Permitted Development rights are currently subject to consultation by the Central Government Department of Communities and Local Government, note that they are not yet legally part of the Planning Acts.

Note 1. The term original house means the house as it was first built or as it stood on 1 July 1948 if it was built before that date. The house may have had an extension built by a previous owner may and this would affect the Permitted Development rights.

Note 2. Designated land includes national parks and The Broads, Areas of Outstanding Natural Beauty, Areas of Special or Scientific Interest, Conservation Areas and World Heritage Sites.

Note 3. Listed Buildings do not have any Permitted Development rights

Note 4. In parts of Welwyn Garden City there is the additional restraint of the Estate Management Scheme which, effectively, removes Permitted Development rights.

Note 5. The L P A could, by issuing an Article 4 Notice, remove the Permitted Development Rights from any specific, or group of, buildings. This is frequently done as a Condition of Consent on new houses and those which to have limited plot sizes.

Note 6. Any extensions and certain internal alterations will still require approval under the Building Regulations and other Acts together with compliance to the Party Wall etc. Act 1997.

The new Permitted Development rights are currently subject to consultation by the Central Government Department of Communities and Local Government, note that they are not yet legally part of the Planning Acts.

There are only two elements that are, in reality, subject to possible change these are :-

Maximum depth of a single-storey rear extension of three metres for an attached house and four metres for a detached house would be increased to six metres for an attached house and eight metres for the detached house.

A further change, which is an addition to the existing list, is that changes to a front elevation by the conversion of a garage to habitable accommodation would be Permitted Development.

Outbuildings. These are considered to be permitted development, not requiring an application for planning permission, providing that all the limits and conditions are met and, in Welwyn Garden City, subject to Note 4 above.

The rules governing outbuildings apply to sheds, greenhouses and garages as well as other ancillary buildings such as swimming pools, ponds, sauna cabins, kennels, enclosures (including tennis courts) and many other kinds of structure for a purpose incidental to the enjoyment of the dwelling house. This includes the keeping of poultry, bees, pet animals, birds or other livestock for the domestic or personal enjoyment of the house.

The limits and conditions are :-

Outbuildings and additions must not exceed 50% of the total area of the land around the house.

Sheds and all other extensions to the original house must be included when calculating this 50%

Any building must not itself be separate self contained living accommodation and must not have a microwave antenna.

Outbuildings must be single storey with a maximum eaves height of 2.5 and a maximum overall height of 4m with a dual pitch roof or 3m in any other case

If the building is within 2m of the boundary the whole building should not exceed 2.5m in height.

Building Regulations.

Class VI. Exempt buildings and works.

Detached, single storey, buildings of up to 30m2 floor area with no sleeping accommodation. Such buildings must be situated more than 1m from the boundary, or, constructed substantially of non-combustible material.

Further information and illustrated explanations can be found on the following links ;


These notes are the Societies understanding of the rules as they now seem to be and may not be interpreted as definitive.  Anyone seeking to enlarge their property under the new Central Government directive must seek the appropriate guidance, engage appropriate professional assistance as necessary and satisfy themselves that they are complying with the law. They may not rely on this document to substantiate their case.

There is the option to obtain a Certificate of Lawful Development by application to the Council. This has substantial benefits in confirming the legality of any works when the property is later sold.

Finally, you can click here to go to the WHBC web page that contains the various planning application forms householders may require.

Report prepared by a delegated member of the Executive Committee of the Welwyn Garden City Society.