What Is the Difference Between an Orangery and a Conservatory?

VS

Left: solid perimeter roof with a central lantern. Right: a predominantly glazed roof and walls.

The main difference is the roof construction and the overall architectural design.

A traditional conservatory is predominantly glass, including its roof. It creates a bright, open space with excellent views of the garden and a strong connection to the outdoors.

An orangery generally has a substantial solid, insulated roof perimeter surrounding a central glazed lantern. It may also incorporate brick or rendered pillars and more solid construction, giving it the appearance and feel of a conventional house extension.

The distinction isn’t absolute. A well-designed modern conservatory can offer excellent thermal performance, while a contemporary orangery can incorporate extensive glazing and wide-opening doors. See the differences in our bespoke orangery collection and conservatory designs.

The name dates back several centuries, when wealthy European households built special structures to protect citrus trees, particularly orange trees, from cold winter weather.

These early orangeries became fashionable features of grand houses and country estates. They were designed to capture sunlight while offering protection from the elements. Over time, their purpose evolved from housing exotic plants to providing elegant spaces for relaxation and entertaining.

Today’s orangeries are very different technically, but many retain the architectural character of their predecessors: generous windows, substantial framing and carefully proportioned glazed roofs.

And no, you certainly don’t need to grow oranges in one.

An orangery is sometimes described as a posh conservatory, but that isn’t really an accurate definition. The difference isn’t simply one of quality or price. It’s primarily about architectural design and construction.

A beautifully designed hardwood conservatory can be every bit as luxurious as an orangery. Equally, a contemporary orangery with slim aluminium frames can look remarkably modern rather than traditional.

Other descriptions you may encounter include garden rooms, sunrooms and glass extensions. These terms sometimes overlap, which is why it is important to look at the actual construction rather than rely on the name.

Sometimes, but not necessarily. An orangery can cost less than a comparable conventional brick-built extension, depending on its size, design, groundworks and specification. However, a premium bespoke orangery can also cost as much as, or more than, a conventional extension.

The biggest cost differences often come from foundations, structural openings, roof design, glazing, heating and internal finishes. At Room Outside, our bespoke orangeries are advertised from £35,000, while bespoke conservatories start from £25,000.

For higher-specification orangery projects, our 2026 planning examples are approximately:

These are illustrative figures rather than fixed quotations. Smaller or simpler designs may cost less, while premium timber, complex glazing, extensive groundworks or substantial structural alterations can increase the price.

A properly designed and insulated orangery can be a comfortable room throughout the winter. The solid insulated roof perimeter generally reduces heat loss compared with a roof constructed almost entirely from glass. Modern glazing, insulated frames and effective heating can further improve comfort.

However, an orangery is not automatically warm simply because it’s called an orangery. Its performance depends on several factors:

1. Roof and floor insulation

   The insulation within the solid roof sections and the floor.

2. The roof lantern

   The quality and specification of the glazed roof lantern.

3. Windows and doors

   The thermal performance of the glazing and frames.

4. Airtightness and installation

   Airtightness, ventilation and the quality of installation.

5. Heating and connection

   The heating system and how the room connects to the house.

The same applies to conservatories. An older conservatory with basic glazing can become cold in winter and uncomfortably hot in summer, but a modern conservatory with high-performance glazing can offer a considerably better experience.

No. An orangery does not have to have a fully glazed roof. In fact, the most recognisable contemporary orangery design combines a solid insulated perimeter roof with a central glazed lantern.

The lantern allows natural light to enter from above, while the surrounding solid roof provides insulation and a plastered ceiling area that can accommodate recessed or concealed lighting. Some bespoke designs use different roof configurations, depending on the architecture of the property and the amount of natural light required.

There is no benefit in choosing a particular label if another roof design would work better for your home. Explore lantern roof options on our orangery design page.

Yes. An orangery needs suitable structural support and foundations, just as a conservatory or conventional extension does. The type and depth of foundations depend on the design, the loads being supported and the ground conditions.

Factors include the soil type, nearby trees, existing drains, adjacent buildings and whether the ground has previously been disturbed. Traditional concrete strip or trench-fill foundations are common, but other engineered solutions may be appropriate for particular sites.

An orangery with substantial masonry pillars or large structural openings may require different foundation and structural design from a lightweight glazed conservatory. It is therefore unwise to assume that a new orangery can simply be installed on an existing patio or conservatory base without investigation.

A proper site assessment is essential before the final construction method and price can be confirmed.

Not always, but removing the separating doors can significantly change the Building Regulations requirements. This is one of the most important issues to understand before choosing your design.

Some conservatories qualify for an exemption from Building Regulations when they meet specific conditions. These generally include:

1. Single storey, at ground level

   The conservatory is single-storey and built at ground level.

2. Under 30m² floor area

   The floor area is under 30 square metres.

3. Thermally separated

   It is separated from the house by external-quality walls, doors or windows.

4. Independent heating controls

   Any heating has independent temperature and on/off controls, and glazing and electrics still comply with the relevant regulations.

If you remove the external doors and create an open-plan connection, that exemption may no longer apply. The project will generally need to be assessed as part of the home’s heated living accommodation, with the appropriate Building Regulations approval. Any new structural opening between the house and the extension also needs approval, even if the extension itself is exempt. Orangeries designed as integrated extensions will also commonly require Building Regulations approval.

This doesn’t mean an open-plan orangery or conservatory is impossible. It simply means the structural design, insulation, glazing, ventilation and energy performance need to be properly considered.

The most suitable heating system depends on how you intend to use the space and whether it forms part of your home’s main heated accommodation. Common options include:

The most important step is to reduce unnecessary heat loss before deciding how much heating is required. A room with poor insulation or inappropriate glazing can be expensive to heat, regardless of which system you install.

If your conservatory is intended to qualify for the usual Building Regulations exemption, its heating arrangement must meet the relevant independence and control requirements.

You can certainly relax or occasionally fall asleep in an orangery, but using one as a permanent bedroom is a different matter.

An orangery intended as regular sleeping accommodation must be designed and assessed for that purpose, including applicable Building Regulations requirements. These may cover fire safety, suitable means of escape, ventilation, thermal performance and other aspects of habitable accommodation.

If your intention is to create a guest bedroom or regular sleeping space, make that clear at the initial design stage. A conventional extension or a differently specified annexe or garden room may be a more appropriate solution.

Both can potentially be constructed under Permitted Development rights, depending on the property and the proposed extension. However, the rules depend on factors such as the size, height and position of the extension, previous alterations to the property and any restrictions affecting the site.

Listed buildings, flats, properties in certain protected locations and homes with restricted Permitted Development rights require particular care.

VS

A built-in room with a lantern, or a bright glazed room in the garden.

Before making a decision, ask yourself:

1. How will you use it?

   Dining room, sitting room, kitchen extension or occasional garden room?

2. How much overhead light do you want?

   A lantern, or a fully glazed roof?

3. Which look suits your home?

   A substantial architectural appearance or more extensive glazing?

4. Separated or open-plan?

   This affects Building Regulations, specification and cost.

5. What comfort do you expect?

   Your expected winter comfort and summer temperature control.

6. What is your realistic budget?

   Including building work and finishing, not just the structure.

These answers are far more useful than deciding on the name alone. For a deeper checklist, see our Conservatory Buyer’s Guide.

Seeing the two side by side often settles the decision faster than any spec sheet. Here are a few of the looks homeowners ask us about most.

See more finished projects in our design gallery, or browse modern conservatory design ideas.

At Room Outside, we believe that choosing between an orangery and a conservatory should begin with an understanding of your home, how you want to live and what you expect from your investment.

Established in 1973, we design bespoke orangeries, conservatories and glass extensions in hardwood timber, aluminium and premium uPVC. Our Design Consultants can help you compare the options, understand the likely costs and identify the most suitable design and glazing specification for your property.