Orangery extensions

An orangery extension sits between a traditional extension and a conservatory: brick or rendered piers, a solid insulated roof perimeter and a large central glass roof lantern. It feels like a proper room all year round while still bringing in plenty of daylight.

Because orangeries are glass-heavy, the building regulations limits on glazing area and heat loss need attention at the design stage. In England, glazing in an extension is generally limited to 25% of the new floor area plus the openings it replaces, unless the design compensates elsewhere.

What is included

• Design of piers, roof perimeter and lantern proportions
• Thermal calculations where glazing is generous
• Foundations, walls and insulated perimeter roof
• Aluminium or timber lantern and full-height glazing
• Heating sized for the glass area
• Opening into the main house

Who it suits

• Period and detached houses with a garden view
• Homeowners replacing an older conservatory
• Those who want daylight without overheating

Design advice

The lantern-to-roof ratio sets the character. A wider solid perimeter gives a calmer, more room-like space and hides downlights and speakers; a bigger lantern feels brighter but needs more care against summer heat.

How much does it cost?

National guide prices including VAT at 20%. Build cost only; design, structural and council fees are extra. Your area page shows prices adjusted for your region.

Planning rules across the UK

England

In England a glazed or orangery-style extension follows the same size limits as any single-storey rear extension: 3 m or 4 m without an application, or up to 6 m and 8 m through prior approval. Building regulations limit glazing to about a quarter of the new floor area plus the openings it replaces, unless whole-house calculations show the design still performs.

Wales

In Wales a glazed or orangery-style extension follows the normal single-storey limits (up to 4 m at the rear). Welsh building regulations also limit glazing and heat loss, so glass-heavy designs need calculations.

Scotland

In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.

Northern Ireland

In Northern Ireland the Planning (General Permitted Development) Order 2015 lets some single-storey rear extensions go ahead without planning permission, up to 3 m on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Larger, side and two-storey extensions normally need planning permission from the council, and building control approval is separate.

Building regulations and neighbours

Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.

In England and Wales, if the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations. Scotland and Northern Ireland have no Party Wall Act.

Questions about orangery extensions