What is an orangery?

The word is used loosely by people selling glazed rooms, so it helps to know what it first meant and what it means on a builder’s drawing now.

Where the name comes from

Citrus trees reached northern Europe as a luxury in the 1600s. They cannot survive a frost, so the owners of large houses grew them in tubs, wheeled them outside for the summer and brought them into a purpose-built shelter for the winter. That shelter was the orangery: a long masonry building with a solid roof, a row of tall south-facing windows and, often, a stove.

Two that survive in London show the type. The Orangery at Kensington Palace was built for Queen Anne in 1704 and 1705. The one at Kew was finished in 1761 to a design by Sir William Chambers. Both are brick or stone buildings with big arched windows. Neither has a glass roof, because glass in large sheets was costly and hard to make until the nineteenth century.

When glass became cheap, the Victorian conservatory took over the job of housing plants, and “orangery” drifted towards meaning a handsome garden room for people.

What an orangery means today

On a modern house, an orangery has four features:

• Masonry corners and piers, in brick, stone or render, between the windows.
• Tall windows and doors filling the spaces between the piers.
• A flat roof around the edge, insulated and finished inside with a plastered ceiling.
• A glazed lantern rising from the middle of that roof.

Outside, the flat roof is usually hidden behind a deep fascia or a parapet, sometimes with a moulded cornice. Inside, the band of ceiling round the lantern takes downlights and gives the room the feel of a proper room and not a greenhouse.

How it differs from a conservatory and a garden room

A conservatory is mostly glass, roof included, on a light frame. An orangery has less glass, more wall and a largely solid roof. A garden room extension goes one step further and has a fully solid roof, taking its light through the walls and perhaps a roof light.

The practical effect is comfort. Each step away from an all-glass roof makes the room easier to heat in winter and slower to overheat in summer. Our comparison of the three goes through this row by row.

The rules

Building regulations. An orangery is an extension. It needs building regulations approval covering foundations, structure, insulation, glazing, ventilation and electrics. The exemption that lets some conservatories skip this does not apply, because an orangery is normally open to the house and heated from it. In Scotland the equivalent is a building warrant.

Planning. Many orangeries need no planning application. In England they fall under the permitted development rules for single-storey extensions, with a depth limit of 4 m on a detached house and 3 m on others. We cover the detail in do you need planning permission for an orangery?

Older and listed houses. Orangeries suit period houses, and that is where consent is most often needed. A listed building requires listed building consent for any extension, and the design, brick and joinery will be looked at closely.

What an orangery costs

As a national guide for 2026, allow about £850 to £2,000 per m² including VAT for a finished uPVC orangery, £1,600 to £2,500 for aluminium and £2,000 to £3,000 for hardwood. A 16 m² hardwood orangery therefore comes to roughly £32,500. The lantern, the size of the doors and the amount of decorative joinery move the figure most. These are guide figures, not quotes, and London and the South East usually cost 20 to 40% more.

Is an orangery right for your house?

It suits a dining room or sitting room where you want daylight from above and a ceiling worth looking at. It suits houses with some formality to them: Georgian, Victorian, Edwardian, and newer houses built in those styles.

It is less suited to a hard-working family kitchen on a south-facing wall, where the lantern can bring more sun than you want over the table. There a solid-roofed garden room extension is usually the calmer choice, and often no dearer. The cost calculator prices both, so you can see the difference for your own size before asking for a quote.