The short answer
An orangery typically costs around £1,800–£2,800 per square metre supplied and built in 2026, with the rate falling as the footprint grows. A small orangery carries a higher per-m² figure because fixed costs — foundations setup, the lantern, doors and the specialist’s mobilisation — are spread over fewer square metres, while a larger build dilutes them. Specification matters too: bi-fold doors, a large lantern, high-performance glass and a kitchen fit-out all raise the rate. These are typical illustrations, not quotes — see the orangery cost guide for whole-build figures.
Cost per square metre is a useful way to compare orangery quotes and sense-check whether a price is in the right range, but it is not a fixed multiplier — the rate changes with size and specification. This guide explains the typical 2026 per-m² range, why smaller orangeries cost more per metre, and how to use the figure without being misled by it. All figures are typical illustrations rather than quotes.
Cost per square metre at a glance
- Typical range £1,800–£2,800 per m²
- Small orangery Higher per-m² rate
- Large orangery Lower per-m² rate
- High specification Pushes the rate up
- 10 m² example Around £20,000–£26,000
- 20 m² example Around £30,000–£40,000
Why the per-m² rate falls with size
An orangery has a large fixed-cost element: foundations setup, the glazed roof lantern, the doors and windows, and the specialist’s mobilisation and survey. These do not scale neatly with floor area, so a small orangery spreads them over fewer square metres and carries a higher rate. As the footprint grows, those fixed costs are diluted and the per-m² figure comes down — even though the total naturally rises. That is why a small orangery can look expensive per metre, while a larger one looks better value on the same basis. See the small orangery cost guide for the lower end.
| Orangery size | Typical rate per m² | Indicative total |
|---|---|---|
| Small (around 10 m²) | £2,000–£2,800 | £20,000–£26,000 |
| Medium (around 16 m²) | £1,800–£2,400 | £28,000–£35,000 |
| Large (around 25 m²) | £1,600–£2,200 | £40,000–£50,000+ |
What raises the rate per square metre
Specification moves the per-m² figure as much as size. A large or multi-pane lantern, bi-fold or sliding doors, high-performance or acoustic glass, underfloor heating, quality flooring and a kitchen fit-out all add cost without adding floor area, so they push the rate up. Groundworks can do the same: poor ground, a sloping site or drainage diversions raise the build cost per metre. When comparing quotes on a per-m² basis, make sure they are for the same specification — otherwise a lower rate may simply reflect a thinner spec.
How to use the figure
To estimate a rough cost, multiply your intended floor area by a rate from the typical range — using the higher end for a small or high-spec orangery and the lower end for a larger, standard one. For example, a 16 m² orangery at £2,000 per m² suggests around £32,000. Treat that as a starting point only: the real figure depends on your ground conditions, design, glazing and finishes, and on the quotes you receive. For whole-build ranges by size see how much an orangery costs; for how an orangery compares with alternatives see is an orangery cheaper than an extension. These are general pointers, not advice for your specific job.
Compare orangery quotes
Per-m² rates only mean something when the specification matches. Use our service to compare itemised quotes from orangery specialists in your area.
Frequently asked questions
What is the average cost per square metre for an orangery?
Around £1,800–£2,800 per square metre supplied and built in 2026, with smaller or higher-specification orangeries at the top of the range and larger, standard builds lower. These are typical illustrations, not quotes.
Why is a small orangery more expensive per square metre?
Fixed costs — foundations setup, the lantern, doors and the specialist’s mobilisation — are spread over fewer square metres on a small build, so the rate per metre is higher even though the total is lower. See the small orangery cost guide.
How do I estimate my orangery cost from the per-m² rate?
Multiply your planned floor area by a rate from the typical range — higher for a small or high-spec build, lower for a larger standard one — to get a rough figure, then compare itemised quotes on the same specification. The real cost depends on ground conditions, design and finishes.
Does the lantern affect the cost per square metre?
Yes. A large or multi-pane glazed lantern adds cost without adding floor area, so it raises the per-m² figure. Door choice, glazing performance and internal finishes have the same effect.
Sources & further reading
- Glass and Glazing Federation (GGF) — consumer guidance on orangery costs and specifications
- FENSA / CERTASS — registered installer schemes and Building Regulations compliance for glazing
- Planning Portal — orangeries and permitted development
- GOV.UK / Building Regulations Approved Documents — standards for glazed structures
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. The glazing should be fitted by a FENSA or CERTASS registered installer. We are an independent information and introduction service, not an installer.