Does an Orangery Need Building Regulations?
Updated: 8 hours ago
An orangery almost always needs building regulations approval in England. The exemption that lets a small, closed-off conservatory avoid building control depends on a translucent roof, glazed walls and external doors between the room and the house, and an orangery fails those tests by design: it has brick piers, a solid insulated roof with a lantern, and is normally open to the house. Wales has its own regulations, so check locally there.
Why is an orangery not exempt like a conservatory?
Because it is built like an extension. In England a conservatory is exempt from building regulations only if it is no more than 30 square metres, at ground level, separated from the house by external-quality doors, has its own independent heating controls, uses safety glazing and has a translucent roof with substantially glazed walls. An orangery's flat, insulated roof with a central lantern is not translucent. Its brick or stone piers are not glazed walls. And most orangeries are joined to the kitchen or living room by a wide opening rather than doors.
Any one of those takes the room out of the exemption, so an orangery is treated as an extension from the first drawing. Our guide to building regulations for a conservatory sets out where the line falls.
What do building regulations cover on an orangery?
The structure, the thermal performance, safety and services. In practice building control will look at:
Foundations and base: footing depth for the ground conditions, the damp-proof course, and the insulated floor slab.
Structure: the brick piers, the ring beam or steel that carries the roof, the lantern's support, and any beam where the house wall has been opened. Structural calculations are needed for these.
Thermal performance: insulation in the roof, the floor and any solid walls, and the U-values of the glazing and the lantern. Under Part L, total glazing (windows, doors and rooflights) should not normally exceed 25% of the extension's floor area, plus the area of any openings it covers up, unless the design shows equal overall performance by calculation.
Safety glazing in doors, side panels and low-level glass, and the lantern glazing where it applies.
Drainage: rainwater from the flat roof and lantern, and any new foul connection if the room includes a sink or utility.
Electrics, certified by a registered electrician or inspected.
Ventilation and, if the orangery contains a kitchen, extraction.
Do you need building regs for an orangery if it is under 30 square metres?
Yes, in almost every case. The 30 square metre limit is one condition of the conservatory exemption, not a threshold below which building regulations stop applying. A 20 square metre orangery with a solid roof and an open link to the house needs approval like a 40 square metre one.
What is the difference between planning permission and building regulations for an orangery?
Planning decides whether the orangery may be built at all (size, height, position, neighbours); building regulations decide how it is built. They are assessed separately, and an orangery that needs no planning permission usually still needs building regulations approval. Our guide on planning permission for an orangery covers the permitted development limits.
How do you get building regulations approval for an orangery?
Through either a building notice or a full plans application to the local authority, or through a registered building control approver (formerly an approved inspector). A building notice is the simpler route and suits a straightforward orangery. A full plans application has the drawings and calculations checked before work starts, which suits a larger orangery, an opening in a structural wall or a listed building. Either way, the inspector typically visits at these stages:
Foundation excavations, before concrete is poured.
Damp-proof course and the insulated floor slab.
Drainage, before it is covered.
Structure: beams, piers and the roof deck before it is closed in.
Completion, when the certificate is issued.
Council fees vary by authority and project size, and structural calculations are an extra cost. On completion you receive a completion certificate; keep it with the deeds, because it is the first document a buyer's solicitor asks for.
Our traditional hardwood orangeries are drawn, calculated and specified for approval from the outset, so the process runs alongside the build rather than after it.
What happens if you build an orangery without building regulations?
The local authority can require the work to be opened up for inspection, altered or, in serious cases, removed. The more common consequence arrives years later, at sale, when the absence of a completion certificate becomes a negotiating point or a reason for a buyer to withdraw. Regularising it after the fact is possible but costs more and may mean exposing work for inspection.
Orangery building regulations questions, answered
Do orangery roof lanterns have to meet building regulations?
The lantern is part of the roof, so its glazing, its U-value and its structural support are all checked as part of the approval.
Can the orangery builder handle building regulations?
A good one manages the application, calculations and inspections. Ask who is responsible before you sign, and ask for the completion certificate at the end.
Does a listed building need building regulations for an orangery?
Yes, and listed building consent as well. Building control may accept alternative approaches to insulation where the fabric of a historic building requires it, but the approval is still needed.
Talk to our design team
If you are planning an orangery, talk to us about your project and we will take the approval through with the build.
