5m x 3m Conservatory Cost UK 2026: £14,000 to £22,000
uPVC from £14,000, Victorian from £17,000, orangery from £30,000. Fifteen square metres, six to ten days on site, a true two-zone layout in a long thin footprint.
Updated May 2026. FMB 2026 cost index, Checkatrade verified quotes, Which? conservatory pricing.
5m x 3m Prices by Style (2026)
| Style | uPVC | Aluminium | Hardwood |
|---|---|---|---|
| Lean-to (5m x 3m) | £14,000 - £17,500 | £17,500 - £23,000 | £23,500 - £31,000 |
| Edwardian | £16,000 - £20,500 | £20,500 - £27,000 | £28,000 - £36,000 |
| Victorian (3-facet) | £17,000 - £22,000 | £22,500 - £29,000 | £30,000 - £38,500 |
| Gable-end | £18,500 - £24,000 | £24,000 - £31,000 | £32,000 - £42,000 |
| P-shaped (5x3 + 1m wing) | £20,000 - £26,000 | £26,000 - £34,000 | £35,000 - £45,000 |
| Orangery | £30,000 - £38,000 | £34,000 - £44,000 | £44,000 - £56,000 |
Source: FMB 2026 cost index, Checkatrade, Which?.
The Two-Zone Layout Strategy
Fifteen square metres in a 5 metre by 3 metre footprint is awkward as a single-purpose room (too long for a self-contained study, too narrow for a centred dining table) and exactly right as a two-zone room. The geometry naturally suggests division: 5 metres of length accommodates two distinct 2.5 metre zones with an invisible boundary between them. This works in a way that a 5 metre by 4 metre footprint does not (too square, no obvious division) and a 6 metre by 3 metre footprint does not (too long, awkward zoning).
The standard dining-plus-lounge two-zone layout: dining table for 4 to 6 at one end against the existing house wall (closest to kitchen access), seating cluster at the garden end with French or sliding doors opening onto a patio. The dining zone uses 1.5 metres by 2.5 metres (table plus chair clearance). The seating zone uses 1.5 metres by 2.5 metres (sofa plus coffee table plus armchair). The remaining 1 metre is the natural walking corridor down the centre.
Alternative two-zone layouts that work well at 5x3: home office plus reading nook (desk at one end, daybed at the other); play room plus parent zone (children's storage and play mat at one end, parent seating at the other); and gym plus pre-workout warm-up (equipment at one end, stretching mat at the other). The 5 metre length means you can dedicate each zone to a single function and avoid the compromises forced by a tighter 3x3 or 4x3 footprint.
The 50% Garden Rule: When 15 m² Becomes a Problem
Permitted development rights cap total extensions plus outbuildings at 50% of the curtilage area. The curtilage is the original land area surrounding the house when it was first built, not the current garden area minus existing structures. For a typical Victorian terrace with a 10 metre by 6 metre rear garden (60 m² curtilage), the 50% cap is 30 m². A 5x3 conservatory adds 15 m². If you have an existing shed (typically 3 to 6 m²), a coal store (1 to 2 m²), and any patio extending more than 30 cm above ground level (some count, depending on local interpretation), the cap can be reached quickly.
The practical check: measure the original garden dimensions (back wall of house to back boundary, side fence to side fence). Multiply for total m². Divide by 2 for the cap. Sum all existing extensions, outbuildings, garages built into the curtilage, and anything raised above ground level. Add the proposed conservatory area. If the total exceeds the cap, full planning permission is required rather than PD. The HomeOwners Alliance estimates this catches roughly 20% of terraced 5x3 proposals.
Where PD is blocked by the 50% rule, the options are: reduce the conservatory size to 4x3 (12 m²) or 3x3 (9 m²) to come under cap; remove an existing outbuilding to free up the cap (a shed demolition and skip costs £200 to £500); or proceed with full planning permission, which adds £206 fee in England, 8 to 12 weeks to the timeline, and usually £400 to £1,500 in design and consultancy fees if a planning consultant is needed.
Cost Breakdown for a 5x3
A typical £17,800 uPVC Edwardian 5x3 with a glass roof breaks down as: frames and glazing £6,100 (34%), roof structure with self-cleaning glass £3,800 (21%), concrete base and dwarf wall £2,600 (15%), doors and side panels £1,500 (8%), electrics £650 (4%), labour 6 to 8 days at two installers £2,650 (15%), skip and fittings £500 (3%). Installer margin 6 to 10% on top. The longer 5 metre house wall pulls more labour and more frames than a 4x3, hence the roughly 25% step up in cost despite only 25% more floor area.
Two cost decisions are particularly important at 5x3. First, the central support column or beam. The 5 metre span exceeds the unsupported limit for most uPVC ridge systems, so installers will either propose a central tie bar (visible across the ceiling at roughly 2.4 metres ceiling height, affects the open feel) or a heavier ridge system at extra £600 to £1,500. The heavier ridge is generally worth the cost; the tie bar visually divides the room and undermines the two-zone design.
Second, door spec on the long wall. French doors at 1.8 metres wide on a 5 metre wall leave 3.2 metres of glazed sidelights. Sliding doors at 2.4 metres wide leave 2.6 metres of sidelight. Bifold doors at 3.6 metres wide leave just 1.4 metres of fixed glazing and effectively open the entire garden wall in summer. The bifold premium over French is £3,500 to £6,500 for a 5x3: meaningful, but transformative for households that entertain outdoors.
5m x 3m Conservatory Cost Calculator
Enter 5 in width and 3 in depth for a 5x3 estimate.
Conservatory Cost Calculator
Enter your details for a 2026 price estimate. Based on FMB, Checkatrade, and Which? data.
Floor area: 12.0 m2
Estimated Total Cost
£14,800 to £30,300
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Cost Breakdown
Excludes: flooring, heating, furniture, VAT where applicable, planning fees. VAT is typically 20% on labour and materials.
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5m x 3m Conservatory FAQ
How much does a 5m x 3m conservatory cost in 2026?
Does a 5x3 need planning permission?
What is the best layout for a 5m x 3m conservatory?
Will 15 m² trigger full building regulations?
What furniture works best in a 5x3 conservatory?
Related Pages
4m x 3m (12 m²)
Down a size. Single-zone room with tighter circulation. £11,000 to £18,000.
5m x 4m (20 m²)
Same length, wider. Square-ish room. £18,000 to £30,000.
P-shaped Conservatory
A 5x3 main section plus a 1m or 2m perpendicular wing creates clean dining and lounge zones.
Planning Permission
Full 50% garden test explainer with worked examples for typical terraced plots.
Edwardian 5x3
Rectangular Edwardian is the natural style fit for a long thin footprint.
Heating
Why the longer 5 metre wall affects heating load and which radiator placement works.