The short answer
An orangery is usually cheaper than a full single-storey extension of the same size, but not always. An orangery typically costs £20,000–£40,000 and is faster to build, because much of the wall is glazing and the roof is a relatively simple flat structure with a lantern. A full extension’s cost varies widely with specification, but for the equivalent footprint it commonly comes out higher. The gap narrows on large, high-specification orangeries with bi-fold doors and a big lantern, which can approach the cost of a modest extension. See orangery vs extension for the wider comparison.
Cost is one of the main reasons homeowners choose an orangery over a full extension, but the saving is not guaranteed and depends on size and specification. This guide compares typical 2026 costs, explains why an orangery usually undercuts a brick extension, and sets out the cases where the two converge — so you can judge which makes sense for your home and budget. All figures are typical illustrations rather than quotes.
Orangery vs extension cost at a glance
- Orangery typical £20,000–£40,000
- Full extension Commonly higher for the same size
- Build time Orangery usually shorter
- Gap narrows on Large, high-spec orangeries
- Light Orangery: more, via the lantern
- Compare on Like-for-like footprint & spec
Why an orangery usually costs less
An orangery typically undercuts a full extension because it involves less masonry and a simpler roof. Where an extension has full external walls and a conventional solid roof tied into the house, an orangery uses brick piers with glazing in between and a flat perimeter roof carrying a lantern. That generally means fewer bricklaying days, a lighter roof structure and less internal integration work, so the build is quicker and the labour lower. It also keeps the orangery’s bright, glazed character. For typical orangery figures by size see how much an orangery costs.
| Factor | Orangery | Full extension |
|---|---|---|
| Typical cost | £20,000–£40,000 | Commonly higher for same size |
| Masonry | Piers plus glazing | Full external walls |
| Roof | Flat with glazed lantern | Solid, matching the house |
| Build time | Usually shorter | Usually longer |
| Integration | Distinct garden room | Seamless with the house |
When the gap narrows
The saving shrinks — and can disappear — in a few cases. A large orangery with extensive bi-fold or sliding doors, a big multi-pane lantern, high-performance glass and a full kitchen fit-out adds cost that brings it close to a modest extension. Difficult groundworks, a sloping site or extensive internal finishing affect both equally. And where you specifically want a conventional solid-roofed room indistinguishable from the rest of the house, a full extension may be the better spend even if it costs more. Weigh light and a faster build against seamless integration — see orangery vs extension.
Cost is not the only factor
An orangery’s lower cost and faster build are real advantages, but the decision should also weigh light, year-round comfort, how the room integrates with the house, planning and value. An orangery brings in more daylight through its lantern and reads as a characterful room; a full extension gives a conventional, fully integrated space. On planning, both are often permitted development within limits — see planning permission for an orangery. On value, a well-built addition of either kind can support a home’s value, though rarely pound-for-pound — see does an orangery add value. These are general pointers, not advice for your specific job.
Compare orangery quotes
The only reliable way to know whether an orangery is cheaper for your home is to compare itemised quotes. Use our service to gather estimates from orangery specialists in your area.
Frequently asked questions
Is an orangery always cheaper than an extension?
Not always, but usually. For the same footprint an orangery typically costs £20,000–£40,000 and is faster to build than a full extension, which commonly costs more. The gap narrows on large, high-specification orangeries. These are typical illustrations, not quotes.
Why is an orangery cheaper to build?
It uses brick piers with glazing rather than full external walls, and a flat perimeter roof with a lantern rather than a conventional solid roof. That means less masonry, a lighter roof and less integration work, so the build is quicker and the labour lower.
When would a full extension be the better choice?
Where you want a conventional, solid-roofed room indistinguishable from the rest of the house, or where the orangery spec would be so high that the cost converges with an extension. See orangery vs extension.
How do I compare an orangery and an extension on cost?
Get itemised quotes for both at the same footprint and finish level. A headline price gap often reflects different specifications rather than a true difference, so comparing like with like is the only reliable way.
Sources & further reading
- Glass and Glazing Federation (GGF) — consumer guidance on orangery costs and specifications
- Planning Portal — extensions, orangeries and permitted development
- GOV.UK / Building Regulations Approved Documents — standards for extensions and glazed structures
- RICS — home improvements and their effect on property value
This is general information, not advice for your specific property or build. Costs, timescales and outcomes vary with your home, the design you choose and your chosen specialist. We are an independent information and introduction service, not an installer.