Why a kitchen suits an orangery
Kitchens need wall. Tall units, an oven housing and a fridge all want something solid behind them, and a conservatory offers none. An orangery has masonry at the corners and can have a full brick wall along one side, usually the boundary side, with the glazing concentrated on the garden elevation.
The lantern does the rest. Set over an island or a dining table it puts daylight where you work, and the plastered ceiling around it takes the downlights and the extractor duct that a glazed roof cannot.
What a kitchen orangery costs
Price it in three parts: the room, the opening and the kitchen. The room is the same as any orangery of its size. The opening means a steel beam designed by a structural engineer, temporary propping and making good. The kitchen is whatever you choose it to be.
Moving a boiler, a gas meter or a soil stack is not in these figures and is never cheap. Find out where yours are before you settle on the position of the opening.
| Part of the job | Typical cost |
|---|---|
| The orangery, uPVC frames | £17,000 to £40,000 |
| The orangery, aluminium frames | £32,000 to £50,000 |
| The orangery, hardwood frames | £40,000 to £60,000 |
| Forming the opening, with steel beam | £1,750 to £4,000 |
| Kitchen fit-out: units, worktops, appliances and fitting | £15,000 to £35,000 |
Building regulations for a kitchen orangery
An orangery that is open to the house is an extension, with no exemption. You need building regulations approval, through the council or a registered building control approver, and the builder normally handles the application.
Four parts of the regulations shape the design. Structure: the beam over the opening and the foundations need calculations. Energy: glazing beyond 25% of the floor area has to be justified, so expect better glass and more roof insulation than the minimum. Ventilation: a kitchen needs extraction to the outside, at 30 litres a second for a hood next to the hob or 60 elsewhere in the room, so plan the duct route through the flat roof or an outside wall. Electrics and gas: new kitchen circuits are notifiable work, and a gas hob must be connected by a Gas Safe registered engineer.
Drains come up more often with kitchens because the sink needs a waste run. If the new room sits over or within 3 m of a public sewer, the water company has to agree to it first.
Laying it out
Start with the sun. A south or west-facing kitchen orangery needs solar-control glass in the lantern and at least one opening vent, or the worktop under it becomes uncomfortable in summer. Facing north, go larger on the lantern; you will want the light.
Put tall units and the cooking run on the solid wall, the sink where the waste can reach a drain easily, and the island or table under the lantern. Keep the hob out from under the glass: extraction through a lantern is awkward and steam marks it.
Size the opening to the room behind it. An opening that takes out the whole back wall looks generous on a drawing and leaves the old kitchen as a dark corridor. Leaving a pier or a return of half a metre each side costs less in steel and gives you somewhere to end a run of units.
Underfloor heating suits these rooms because radiators compete with units and glass for wall space. It needs deciding early, since it sets the floor build-up and the threshold level at the doors.
Living through the build
The new room goes up first, behind your existing back wall, and you keep a working kitchen for most of the job. The disruption comes at the end: the wall comes out, the floor levels are joined and the new kitchen is fitted. Expect two to four weeks with no usable kitchen, and ask the builder to leave the old sink and a socket live for as long as possible.
Sources and how the figures are worked out
Typical national ranges for 2026, including VAT. London and the South East usually cost 20 to 40% more. A guide, not a quote. Planning and building regulation notes are general guidance for England unless we say otherwise.