An orangery joined to a house by external-quality doors under building regulations
Planning & building regs · Guide

Building regulations for an orangery

When an orangery is exempt and when Building Regulations apply — glazing ratio, separating doors and Building Control sign-off.

Updated June 2026Sourced from trade and government guidance
OA
Orangery Answers editorial
Reviewed against GOV.UK Building Regulations Approved Documents, the Planning Portal, FENSA, CERTASS and the Glass and Glazing Federation (GGF). We are an independent information and introduction service, not an orangery installer.

The short answer

Some orangeries are exempt from building regulations and some are covered, depending mainly on how much glazing they have and whether they are separated from the house. An orangery built at ground level, under a set floor-area threshold, with a high proportion of glazing and separated from the house by external-quality doors and walls, can fall within the conservatory-style exemption. An orangery that is large, has a high proportion of solid wall and roof, or is opened up into the house so it becomes part of the heated space, is more likely to require full building regulations approval and Building Control sign-off. Because orangeries blend masonry and glass, the position is often borderline — confirm it with your local Building Control. See planning permission, which is a separate matter.

Building regulations set standards for structural safety, energy efficiency, drainage, ventilation and more. Whether they apply to an orangery is not automatic: it turns on the orangery’s size, glazing ratio, how it is separated from the house, and whether the heating system is extended into it. This guide explains the exemption, when full approval is needed, and how sign-off works. It is general information based on national guidance; your local Building Control is the definitive source for your build.

Building regulations at a glance

When an orangery may be exempt

The exemption that applies to conservatories can extend to some orangeries. To fall within it, an orangery typically needs to be built at ground level and under a set internal floor-area threshold, have a high proportion of glazing in the walls and roof, be thermally separated from the house by external-quality doors and walls, and have an independent heating system with its own controls rather than an extension of the main central heating. Where an orangery meets these tests it can be exempt from most building regulations, though the glazing itself remains notifiable work. Because orangeries deliberately include more solid wall and a partly solid roof than a conservatory, the glazing-ratio test is the one most likely to tip a build into being covered.

FeaturePoints toward exemptionPoints toward approval
Floor areaBelow the thresholdLarge footprint
Glazing ratioHigh proportion of glassMostly solid wall & roof
SeparationExternal-quality doors retainedOpened into the house
HeatingIndependent, own controlsMain heating extended in
LevelBuilt at ground levelOther arrangements

When full approval is needed

An orangery is more likely to require full building regulations approval where it exceeds the floor-area threshold, where it has a high proportion of solid wall and roof rather than glazing, where it is opened up to the house by removing the separating doors so it becomes part of the heated living space, or where structural work to the existing house — such as a large opening or a steel beam — is involved. In those cases the build must meet the relevant Approved Documents and be signed off by Building Control, either through your local authority or an approved inspector. Many homeowners who want the orangery fully integrated and open-plan accept that approval is needed, because that integration is part of the appeal.

The glazing is always notifiable: regardless of whether the structure is exempt, replacement and new glazing should be fitted by a FENSA or CERTASS registered installer who self-certifies that work and issues a certificate. Keep all certificates and any Building Control completion certificate — you will need them when you sell. Confirm the position for your build with your local Building Control before you start.

How sign-off works

Where building regulations apply, the work is checked against the Approved Documents and, on completion, you receive a completion certificate from Building Control. For the glazing, a FENSA or CERTASS registered installer self-certifies and issues a separate certificate. If you use an installer who is not registered, you must arrange Building Control sign-off for the glazing separately. Keeping these certificates is important — a buyer’s solicitor will typically ask for them. This is general information, not advice for your specific build; whether building regulations apply, and how, depends on your orangery and your local Building Control’s assessment.

Compare orangery quotes

A registered orangery specialist can advise on whether building regulations apply to your design and arrange the necessary sign-off. Use our service to compare quotes from specialists in your area.

Free to use. No obligation. We are an independent guide, not an installer.

Frequently asked questions

Does an orangery need building regulations approval?

It depends. An orangery can fall within the conservatory-style exemption if it is at ground level, under the floor-area threshold, highly glazed, separated from the house by external-quality doors and independently heated. If it is large, mostly solid, or opened into the house, full approval is usually needed. Confirm with your local Building Control.

What makes an orangery exempt from building regulations?

Being built at ground level, under the set floor-area threshold, with a high glazing ratio, thermally separated from the house by external-quality doors and walls, and with its own independent heating. The glazing itself remains notifiable work regardless.

Do I need a certificate for the glazing?

Yes. New and replacement glazing is notifiable, so it should be fitted by a FENSA or CERTASS registered installer who self-certifies and issues a certificate. If the installer is not registered, you must arrange Building Control sign-off separately. Keep the certificate for when you sell.

Is building regulations the same as planning permission?

No. They are separate. An orangery can need planning permission, building regulations approval, both or neither. See planning permission for an orangery.

Sources & further reading

This is general information, not advice for your specific property or build, and the rules vary across the UK and over time. Your local Building Control is the definitive source. The glazing should be fitted by a FENSA or CERTASS registered installer. We are an independent information and introduction service, not an installer.