Conservatories

A conservatory is an extension in planning law, so it follows the same permitted development rules as any other extension to a house in England. Most single-storey conservatories at the back of a house need no planning application if they stay within the limits below. Depths are measured from the original house: as it was first built, or as it stood on 1 July 1948 if older.

The limits

	Terraced or semi-detached	Detached
Depth beyond the rear wall	3m	4m
Depth with prior approval	6m	8m
Height	4m	4m

• Eaves no higher than 3m if the conservatory is within 2m of a boundary.
• No higher than the roof of the house, and eaves no higher than the existing eaves.
• Not beyond the front wall of the house, or beyond a side wall that faces a road.
• To the side: single storey, no higher than 4m and no wider than half the width of the original house.
• No verandah, balcony or raised platform.
• Together with other extensions and outbuildings, no more than half the land around the original house.

A conservatory joined to an earlier extension is measured together with it.

Materials

Other extensions must use materials similar in appearance to the house. Conservatories are exempt from that condition, so the glass and frames do not have to match.

When permission is needed

• The home is a flat or maisonette. These rights apply to houses only.
• The house was converted from another use, such as offices, without a planning application, or added as new storeys on an existing building.
• Conservation areas, National Parks, National Landscapes, the Broads and World Heritage Sites: no side conservatories.
• The 6m and 8m route is not available on that protected land or on a Site of Special Scientific Interest.
• The house is listed. Listed building consent is needed for an extension likely to affect its character.
• An Article 4 direction, or a condition on an earlier permission, has removed the rights.

Prior approval

The 6m and 8m depths go through the council first. It notifies the neighbours, who get at least 21 days to comment. If one objects, the council judges the effect on their homes. Work can start once the council replies, or after 42 days without a decision.

Search your postcode to see which conservatories were approved nearby.

Source: The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 1, legislation.gov.uk; Permitted development rights for householders, technical guidance, Ministry of Housing, Communities and Local Government; Conservatories and Listed building consent, Planning Portal.