2026 conservatory extension pricing guide
Conservatory extension cost: a clear 2026 UK price guide.
Compare fully installed conservatory extension prices by size, material and cost per square metre, then use the instant estimator to narrow the range for your project.
Quick answer
A fully installed conservatory typically costs from £18,000 to £100,000+ in 2026.
The range is wide because size, frame material, glazing, groundwork and finish all matter. These benchmarks include construction and installation rather than frame-only kit prices.
Start with a realistic range, then refine it around your home.
A headline price is useful, but a reliable budget also has to account for foundations, access, structural work, glazing specification, electrics and finish. The estimator below uses the same 2026 figures shown in the detailed price cards.
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Estimate only. The final price depends on access, foundations, glazing and finish. A site survey is needed for a fixed quotation.
01 / Compact projects
How much does a small conservatory cost?
A small conservatory is usually 3m × 3m to 3.5m × 3.5m, or roughly 9–12m². It can work as a garden room, breakfast space or home office without dominating a modest garden.
Even with a compact footprint, foundations, glazing and installation remain substantial parts of the budget. The figures below include the base, frame, glass roof, preparation for electrics, plastering and finishing.
Lowest initial cost
uPVC
- Installed range
- £18,000–£24,000
- Typical mid-range total
- £21,000
Slim-frame modern
Aluminium
- Installed range
- £26,000–£33,000
- Typical mid-range total
- £29,500
Traditional premium
Hardwood / timber
- Installed range
- £31,000–£40,000
- Typical mid-range total
- £35,000
Minimal structural glazing
Glass box extension
- Installed range
- £38,000–£52,000
- Typical mid-range total
- £45,000
A short site survey turns broad ranges into a fixed number in writing. Request your fixed-price quote or call 01243 538999.
02 / Prices by footprint
Conservatory extension cost by size: small, medium and large
Size is the biggest single driver of cost. Each card below keeps the complete price comparison in one easy-to-scan column.
uPVC
Installed price by size
- Small / 3m × 3m
- £18,000–£24,000
- Medium / 4m × 4m
- £25,000–£35,000
- Large / 5m × 5m
- £37,000–£48,000
Aluminium
Installed price by size
- Small / 3m × 3m
- £26,000–£33,000
- Medium / 4m × 4m
- £37,000–£49,000
- Large / 5m × 5m
- £52,000–£70,000
Hardwood / timber
Installed price by size
- Small / 3m × 3m
- £31,000–£40,000
- Medium / 4m × 4m
- £44,000–£58,000
- Large / 5m × 5m
- £65,000–£85,000
Glass box / structural glazing
Installed price by size
- Small / 3m × 3m
- £38,000–£52,000
- Medium / 4m × 4m
- £55,000–£80,000
- Large / 5m × 5m
- £85,000–£125,000+
Groundwork, installation, a glass roof, internal finish and VAT. Large glass box projects may need extra steel and deeper foundations.
03 / Pricing benchmark
Conservatory extension prices per square metre in 2026
A rate per square metre is useful when comparing differently shaped schemes. These ranges include the substructure, frame, insulated glass roof, glazing, electrics, plastering and a mid-level decorative finish.
uPVC
£1,400–£1,800 per m²
- Example at 20m²
- £28,000–£36,000
Aluminium
£2,100–£2,500 per m²
- Example at 20m²
- £42,000–£50,000
Hardwood / timber
£2,600–£3,200 per m²
- Example at 20m²
- £52,000–£64,000
Glass box / structural glass
£3,200–£4,500 per m²
- Example at 20m²
- £64,000–£90,000
Multiply the intended floor area by the relevant rate, then allow for site-specific items such as access, foundations and upgraded heating.
05 / Compare project types
Conservatory vs orangery vs glass extension costs
The right route is not only about price. Consider the architecture, amount of masonry, glazing system, build time and how the room will be used.
Looking for a glass extension rather than a conservatory? A glass extension is fully integrated into the house with no thermal separation, always needs Building Regulations approval, and prices differently. Our glass extension cost guide covers that route in full, including per-m² rates by region.
Best for a cost-conscious garden room and a traditional conservatory appearance.
Best for a more substantial room with masonry, slim frames and a lantern roof. Compare orangery prices.
Best for a contemporary architectural statement and a strong indoor–outdoor connection. See the glass extension cost guide.
Best for conventional permanent living space where a longer, more involved build is acceptable.
Frequently asked questions
Conservatory extension cost questions, answered.
How much does a conservatory extension cost in 2026?
A conservatory extension typically costs £18,000 to £100,000+ fully installed in 2026. A small 9-12m² uPVC build starts around £18,000; a medium 16-20m² aluminium extension usually lands between £30,000 and £50,000; and a large 25m²+ hardwood or structurally glazed extension runs from £55,000 upwards. Size, frame material and glazing specification account for most of the spread.
What are typical conservatory extension prices per square metre?
Conservatory extension prices run roughly £1,400-£1,800 per m² for uPVC, £1,900-£2,600 per m² for aluminium, £2,400-£3,200 per m² for hardwood, and £3,000-£4,500+ per m² for structural or glass box construction. Smaller footprints cost more per m² because foundations, design and site setup are spread across less floor area.
What does a modern glass conservatory cost?
A modern glass conservatory with slim aluminium frames and a glazed or lantern roof typically costs £30,000-£65,000 for 16-20m². Moving to a fully structural or frameless build pushes the same footprint to £60,000-£100,000+. The premium buys slimmer sightlines, larger glass panes and better solar control rather than more floor area.
Is a conservatory extension cheaper than a brick extension?
Usually yes at standard specification. A uPVC or aluminium conservatory extension is often 20-40% cheaper per m² than a comparable brick extension, mainly because there is less masonry, roofing and internal finishing. The gap narrows sharply once you specify structural glazing, a solid roof or full building-regulations integration.
How much does a small conservatory cost in 2026?
A small bespoke conservatory of roughly 3m × 3m costs £18,000–£35,000 fully installed. uPVC starts around £18,000, aluminium around £26,000 and hardwood around £31,000.
What is the average conservatory cost per square metre?
Expect £1,400–£1,800 per m² for uPVC, £2,100–£2,500 for aluminium and £2,600–£3,200 for hardwood. Glass box extensions start around £3,200 per m².
Are uPVC conservatories cheaper than aluminium?
Yes. uPVC is usually 30%–50% less expensive upfront. Aluminium costs more but offers slimmer frames, a longer lifespan and a more contemporary appearance.
Do I need to pay planning fees for a conservatory?
Most conservatories fall under permitted development and have no planning application fee. Protected properties and larger or open-plan projects may need planning and Building Control approval.
What hidden costs do budget quotes exclude?
Common omissions include groundworks, removal of an existing structure, upgraded glass, underfloor heating, electrical work and internal finishes. Ask for a fully inclusive fixed-price contract.
Which costs more, a glass box extension or a conservatory?
A glass box extension often costs 60%–100% more than a standard uPVC conservatory because of the structural glass engineering, premium frames and specialist installation.
How much value does a conservatory add?
A well-specified conservatory or glass extension can add around 5%–12% to property value, although the result depends on location, property type, design and build quality.
Continue your research
Useful cost and planning guides.
From estimate to fixed price
Get a conservatory price built around your home.
A free consultation and site survey can account for the factors that a generic calculator cannot: access, foundations, glazing, finish and the way you want to use the room.
Prices are indicative 2026 ranges, including VAT, and are not a quotation. Every property, specification and site is different.
Get a written conservatory quote
Tell us the rough size, the room it joins and where you are, and we will send a realistic range for your project rather than a headline figure.
Prefer to talk? Call 01243 538999. We design and build from our Chichester workshop, and have done since 1973.
