Orangery (UK Guide 2025)
Design, Sizes & Build Rules
Orangeries are one of the most popular ways for UK homeowners to add bright, comfortable living space. They sit between a traditional brick extension and a glazed conservatory: you get plenty of glass and daylight, but with the insulation and solid feel of a true home extension.
This guide explains what an orangery is, how it differs from a conservatory or a standard extension, design styles, materials, planning rules, costs, glazing, pros and cons, and how long an orangery should last.
Table of Contents
What is an Orangery? (Definition & Differences)
An orangery is a single-storey extension that combines solid construction (brick or blockwork, insulated flat roof) with large glazed areas and usually a central roof lantern. It feels like a normal room that just happens to have more glass and a view of the sky.
Historically, orangeries were built on large estates to grow citrus trees. Today, they are used as:
open-plan kitchen-diners
family living rooms
garden rooms or snug lounges
They are usually built at the rear of the home and designed to look like a natural continuation of the house.
How it differs from a conservatory:
Conservatories are mostly glass, including a fully glazed roof.
Orangeries have a solid, insulated roof with a glazed lantern or roof windows.
Conservatories often feel more like a separate sunroom.
Orangeries feel more like a proper extension and are easier to keep comfortable year-round.
How it differs from a standard extension:
A standard extension has solid walls and roof, with normal windows and doors.
An orangery still uses a solid base and roof structure, but keeps a large lantern and more glass to bring in extra light.
An extension is the most “house-like”; an orangery is the “light-filled extension” version.
Orangery Design Variations
Traditional Orangery
A traditional orangery takes its cues from period properties:
brick or stone pillars and a solid base
tall sash or casement windows between the piers
a flat warm roof with a central, decorative roof lantern
deep cornice or parapet around the roof edge
From outside, it looks like a classic, formal garden room. Inside, you usually get a plastered ceiling around the lantern and a very cosy, elegant feel.
Best for: period homes, Georgian/Victorian terraces, and anyone wanting a more traditional look.
Modern Orangery
Modern orangeries are all about clean lines and maximum glass:
slim aluminium or modern uPVC frames
large fixed panes and wide sliding or bifold doors
flat warm roof with a minimalist lantern or flat rooflights
simple fascias instead of ornate cornices
They suit new builds and contemporary homes where you want that “inside-outside” look with very thin frames and big openings.
Best for: modern houses, open-plan kitchen-diners, and properties with bi-fold or sliding doors out to a terrace.
Hybrid Orangery
A hybrid orangery mixes traditional and modern details:
brick base and pillars for solidity
modern large panes and doors for views
lantern or roof windows that can be styled either way
For example, you might match the house brick and use a neat modern aluminium lantern. Or keep a period-style cornice but add contemporary bifold doors.
Best for: homes that sit between old and new, or where you want the character of a traditional orangery but with modern glazing and doors.
Bespoke Orangery
Almost all orangeries are bespoke to some degree, but a truly bespoke design:
follows an unusual footprint (L-shape, wraparound, corner)
deals with tricky sites (changes of level, existing extensions)
integrates features like integrated seating, roof trusses, or special glazing
If you have a very specific layout in mind, an architect or specialist designer can create a one-off orangery tailored to your property and lifestyle.
Materials Comparison: uPVC vs Aluminium vs Timber
Most orangeries are a mix of:
masonry (foundations, walls)
frame material for windows, doors and lantern
roof structure and covering
The key frame materials are uPVC, aluminium, and timber.
uPVC:
Pros
usually the cheapest option
good thermal insulation
very low maintenance
can be foiled in different colours/wood effects
Cons
thicker frames than aluminium, so slightly less glass area
can discolour or look tired after decades
not as “premium” looking as aluminium or timber
Typical lifespan: around 20–25 years for the frames
Best for: budget-friendly projects and modern properties where low upkeep is important.
Aluminium:
Pros
very strong, so slim frames and large panes are possible
excellent durability (40+ years with minimal maintenance)
huge range of colours, including dual-colour and metallic finishes
ideal for large aluminium bifold or sliding doors
Cons
more expensive than uPVC
relies on a thermal break for good insulation
Typical lifespan: 30–50+ years
Best for: modern designs, large glass areas, and long-term durability.
Timber:
Pros
naturally very good thermal insulation
beautiful, warm appearance that suits period homes
can be painted or stained and refreshed over time
Cons
higher upfront cost
needs regular maintenance (painting or staining)
if neglected, can rot or warp
Typical lifespan: 40–60+ years for quality hardwood, with good maintenance
Best for: heritage properties, conservation areas, and high-end bespoke projects.
You can also mix materials, e.g.:
brick base and pillars
aluminium lantern
uPVC windows and Aluminium doors
This lets you balance budget, looks and performance.
UK Planning Permission & Building Rules for Orangeries
You need to think about both planning permission and building regulations.
Planning permission
Many single-storey rear orangeries fall under Permitted Development (PD), so full planning permission is not always required.
Typical PD rules for a rear orangery:
single-storey
not higher than 4m overall
does not extend more than 3m from the original rear wall on a semi/terrace, or 4m on a detached house
the total area of extensions, sheds etc. does not cover more than half of the garden
no verandas, balconies or raised platforms
PD does not apply to:
flats and maisonettes
listed buildings
some properties in conservation areas or other designated areas
If your design goes beyond PD limits, or your PD rights have been removed, you’ll need to submit a normal planning application.
Even if you use PD, it’s a good idea to get a Lawful Development Certificate from your council as proof the orangery was allowed. This helps when you sell the property.
Building Regulations
In most cases, an orangery does need Building Regulations approval.
That means checks on:
foundations and structure
insulation in floor, walls and roof
U-values of windows and glazed doors
safety glazing in doors and low-level glass
electrical work (Part P)
ventilation and heating
Because an orangery usually has a solid roof and often opens directly into the main house, it is treated more like an extension than a conservatory.
A good installer or your builder should handle the building control application and arrange inspections. Always ask for the completion certificate at the end.
For a refresher on double-glazing rules and energy performance, see our Double Glazing Cost Calcualtor.
Orangery vs Conservatory vs Extension
Quick comparison:
Conservatory:
mostly glass walls and a glazed roof
separated from the house by external-quality doors in many cases
cheapest way to add a lot of glass
can be prone to temperature swings if not specified well
Orangery:
mix of brick or solid walls and large glazing
insulated flat or warm roof with a central lantern
usually open to the main house as part of an open-plan layout
more stable temperature and more “room-like” than a conservatory
Extension:
solid walls and solid roof
windows and doors like the rest of the house
can be single or two storeys, and used for any type of room
often adds the most straight-line value but is usually the most expensive option
Think of it like this:
Conservatory = glass room.
Orangery = light-filled extension.
Extension = full brick extension with standard windows and roof.
Orangery Costs in the UK and Pricing Factors
Costs vary by size, region, specification and materials, but broad guide ranges are:
Small orangery (around 3m x 3m)
Rough guide: around £15,000–£25,000 for a fully built, decent-spec room.Medium orangery (around 4m x 4m)
Rough guide: around £25,000–£35,000.Larger orangeries (5m x 5m and above)
Rough guide: from around £35,000 upwards, and £50,000+ for high-spec hardwood or very large designs.
These are ballpark figures for a full build including base, structure, glazing and basic electrics. High-end materials, complex roof shapes, large bifolds, underfloor heating and luxury finishes will push the total up.
Key cost drivers:
size and shape (simple rectangle vs complex layout)
frame material (uPVC < aluminium < timber, in cost)
type and size of doors (bifolds and big sliders add a lot)
roof design (single lantern vs multiple lanterns/skylights, or tiled roof)
glazing spec (standard double vs solar-control, acoustic or triple glazing)
level of internal finish (plaster, flooring, lighting, kitchen integration)
site conditions and access (foundations, drainage, awkward access)
Always get multiple detailed quotes that spell out exactly what is included.
Glazing Options & Insulation Performance
Glazing is a big part of how comfortable your orangery feels.
Double vs triple glazing:
Modern double glazing (with Low-E coating, argon gas and warm-edge spacer) usually has a glass centre U-value around 1.2–1.4 W/m²K, and a whole-window U-value around 1.4–1.6 W/m²K.
Triple glazing can bring the U-value closer to 0.8–1.0 W/m²K, but adds weight and cost.
If you’re comparing window options for the rest of the house, our uPVC Windows guide explains A-ratings, U-values and BFRC labels in more detail.
For most UK homes, good double glazing is more than adequate, especially if you combine it with:
Low-E glass to keep heat in
solar-control coatings on south or west faces and on roof glass
self-cleaning coatings on the roof lantern to reduce maintenance
Acoustic performance:
Standard double glazing already cuts a lot of external noise.
If you live by a busy road or under a flight path, you can specify acoustic laminated glass, which uses a special interlayer to further dampen sound.
Building Regulations:
New windows and glazed doors for an orangery must meet current Part L requirements, usually U-value 1.6 W/m²K or better.
The solid parts of the roof and walls are insulated to much lower U-values (better insulation) than the glass, so overall the room can perform very well.
Security & Certification
A well-designed orangery should be just as secure as the rest of your home. The windows, doors and roof glazing are all potential entry points, so it’s worth checking that the products and installation follow modern UK security standards—not just “look” secure.
Doors & windows: what to look for
PAS 24 tested doors and windows
Ask whether the external doors and opening windows in your orangery meet PAS 24 (the main security standard for domestic doors and windows in the UK). It means the complete door-set or window-set has been tested against forced entry, not just the individual components.Multi-point locks and secure cylinders
Look for multi-point locking (hooks/bolts that lock into the frame) and 3-star or Sold Secure rated cylinders that comply with TS 007 or equivalent. These help protect against common attacks such as snapping or drilling.Glazing and beading
In critical areas (doors, low-level glazing and next to doors), panes should be toughened or laminated safety glass to meet Building Regulations and reduce the risk of both break-ins and injury. Internally beaded frames (where the glass is fitted from inside) make it much harder to remove the glass from outside.
Roof lanterns & flat rooflights
On an orangery, the lantern or flat rooflights are part of the external envelope, not just a decorative feature. For extra peace of mind, many higher-spec systems offer:
Laminated inner panes to help prevent fall-through and resist impact
Secure fixings and caps that are harder to remove from outside
Lockable roof vents where openers are used
It’s worth asking for written confirmation of the roof system used and whether it has been independently tested or certified.
Accreditations & paperwork
A good installer should be able to show:
Product datasheets confirming PAS 24 (where relevant)
Membership of schemes such as Secured by Design (police-backed crime prevention) for some door and window ranges
Competent Person Scheme registration (e.g. FENSA or CERTASS) for the installation, so your orangery doors and windows are correctly registered with Building Control
Before you sign, ask the installer to confirm in writing which standards your orangery doors, windows and roof glazing comply with, and make sure security features are listed clearly on the quote—not buried as a vague “upgrade”.
Pros and Cons of Orangeries
Advantages
Extra, usable living space all year round
Bright and airy, with a view of the garden and sky
Feels more integrated and “solid” than a conservatory
Better thermal performance than a fully glazed room
Highly customisable design (style, size, materials)
Can add strong appeal and resale value to your home
Disadvantages
More expensive than a basic conservatory
On-site building work and disruption for several weeks
Slightly less glass than a full conservatory (if you love the pure glasshouse look)
May need planning permission depending on size and location
Multiple elements to maintain over the long term (roof covering, gutters, frames, etc.)
For many UK homeowners, an orangery is the “sweet spot”: more comfortable and useful than a conservatory, but lighter and more special-feeling than a solid extension.
Still deciding between a conservatory and an orangery? Our Conservatories guide compares costs, styles and replacement options.
Lifespan & Maintenance of Orangeries
If built properly, an orangery is a long-term addition.
Typical component lifespans:
foundations and brickwork: effectively the life of the house
uPVC frames: around 20–25 years
aluminium frames: 30–50+ years
timber frames: 40–60+ years with good maintenance
double-glazed units: 20–30 years before some may need replacing
flat roof coverings (EPDM, GRP, high-quality felt): often 20+ years
Maintenance tips:
Check gutters and outlets yearly and clear any leaves.
Inspect seals around windows, doors and the lantern for any cracks or gaps.
Clean glass regularly; self-cleaning roof glass still benefits from occasional rinse-down.
Repaint or restain timber on the schedule recommended by the manufacturer.
Deal with any tiny water marks or hairline cracks early rather than ignoring them.
You do not usually replace an orangery in one go. Over decades you might replace or upgrade individual elements (glass units, roof covering, maybe a set of doors), while the main structure remains.
FAQs
Q1: Do I need planning permission for an orangery?
A: Not always. Many single-storey rear orangeries fall under Permitted Development rules, as long as they stay within the size and height limits and your property type is eligible. If you plan something larger or live in a conservation area, on a listed building or in a flat, you are more likely to need full planning permission. When in doubt, check with your local planning authority and consider applying for a Lawful Development Certificate for peace of mind.
Q2: Do orangeries need Building Regulations approval?
A: Almost always yes. Because an orangery has a solid insulated roof and is usually open to the main house, it is treated like an extension for Building Regulations. That means building control will check the structure, foundations, insulation, glazing safety, electrics and ventilation. Your installer or builder should handle the paperwork and inspections and give you a completion certificate at the end.
Q3: Is an orangery warmer than a conservatory?
A: Typically yes. An orangery has less glass and more insulated elements than a traditional fully glazed conservatory. The solid warm roof and insulated walls, combined with modern double glazing, make it much easier to keep an even temperature through the year. A well-specified conservatory can also be comfortable, but in general an orangery feels more like a normal room in winter and less like a greenhouse in summer.
Q4: How long does an orangery last?
A: A well-built orangery should last for many decades. The foundations and brickwork are permanent. Frames can last 20–25 years for uPVC, 30–50+ years for aluminium and 40–60+ years for quality timber with good maintenance. Glazing units often last 20–30 years before any seals might fail. Roof coverings on flat sections are often renewed after 20 or more years. With basic care, your orangery should comfortably see out the lifetime of your ownership.
Q5: Do orangeries add value to a property?
A: In most cases, yes. An orangery adds extra floor space and creates a high-quality living area, which buyers find attractive. The exact uplift depends on the size, quality, and how well it fits the house, but an orangery is usually seen as a proper extension rather than a “bolt-on” sunroom. It can also make your home stand out in local listings, which helps when you eventually come to sell.