Adding a conservatory to your house is treated the same as adding a single storey extension, and the same rules apply. Development of a conservatory is considered to be permitted development, not needing an application for planning permission, subject to the limits and conditions listed below:

  • The conservatory cannot extend beyond a wall comprised in the principal elevation of the original dwellinghouse. Guidance on what constitutes the principal elevation is contained within the householder guide.
  • No more than half of the area of land around the original house can be covered by a conservatory.
  • The conservatory cannot be higher than the height of the eaves of the existing dwellinghouse.
  • If your conservatory is located within 2 metres of a boundary of your house, the eaves height of the conservatory cannot exceed 3 metres.
  • Conservatories are not permitted development within the curtilage of a listed building.
  • The length and height of your conservatory must be no more than 4 metres.
  • For side conservatories, the width of your conservatory cannot be more than half of the width of the original dwellinghouse.
  • Side conservatories have additional restrictions on size in conservation areas, national parks, areas of outstanding natural beauty or World Heritage Sites. ¬†They may extend from the side elevation of the original dwellinghouse by no more than 3 metres and must be set back from the principal elevation of the original dwellinghouse by at least 1 metre.

Please note: the permitted development allowances described here apply to houses not flats, maisonettes or other buildings. View guidance on flats and maisonettes here.

Where work is proposed to a listed building, listed building consent may be required. Contact your Local Planning Authority for further advice.

Please be aware that if your development is over 100 sqm, it may be liable for a charge under the Community Infrastructure Levy.

Removal of permitted development rights

You need to be aware of whether the permitted development rights have been removed from your property by the Local Planning Authority. If they have been removed, you must submit a planning application for the work.

The Local Planning Authority may have removed some of your permitted development rights as a condition of the original planning permission for your property. This information will be available on the planning register held by the Local Planning Authority. Permitted development rights may also have been removed by an 'Article 4' direction. These are most common in conservation areas where the character of an area could be threatened by unmanaged development. Your solicitor should have informed you of whether an article 4 direction exists when you purchased your property, but you can check with the Local Planning Authority if you are not sure

Householder guide

The Welsh Government has produced a technical guide, and a householder guide, available here, to help you understand how permitted development rules might apply to your circumstances.

* 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). Although you may not have built an extension to the house, a previous owner may have done so.

* Designated land includes national parks and the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites.