How we source conservatory cost figures
Every cost band on this site is triangulated across at least three independent UK reference sources: a trade body, a consumer publisher, and a practitioner-quote aggregator. No band rests on a single source. This page lays out which sources we use, how the calculator math works, what is in scope, what is out of scope, and the refresh cadence.
Sources
| Publisher | Type | What we use it for |
|---|---|---|
| Federation of Master Builders (FMB) | Trade body | Annual FMB cost guides and the FMB House Price Index publish indicative installer day rates and trade material cost movement across UK regions. We use FMB rate guidance for the labour component of cost bands and for region multipliers. |
| Which? Trusted Traders / Which? home-improvement reports | Consumer research | Which? has published conservatory-cost research repeatedly across the last decade, including the well-known reporting on conservatory-sales high-pressure tactics. We use Which? for upper/lower bound sanity checks on quoted bands and for the value-uplift evidence on the home page. |
| Checkatrade | Practitioner aggregator | Checkatrade publishes average-job-cost data per conservatory job category, drawn from their verified-member trader quotes. We cross-reference Checkatrade midpoints against the FMB and Which? bounds. |
| MyJobQuote | Practitioner aggregator | Independent UK quote-aggregator. We sanity-check Checkatrade midpoints against MyJobQuote, and where the two diverge by more than 15%, the lower band is widened to cover the gap rather than splitting the difference. |
| Real Homes | Consumer publisher | Real Homes publishes conservatory cost articles refreshed annually, with editor-verified installer interviews. Useful as a cross-check on the style-specific bands (Victorian vs Edwardian vs orangery), particularly on the medium-to-premium end of each band. |
| Homebuilding and Renovating | Consumer publisher | Homebuilding and Renovating publishes detailed sizing and material cost data for conservatories, particularly oak / hardwood frames and orangeries. We use HBR for the upper-end material bands (hardwood / oak orangery, large-span aluminium) where Checkatrade and MyJobQuote tend to underrepresent. |
| FENSA (Fenestration Self-Assessment scheme) | Industry scheme | FENSA-member installer guidance and the FENSA building-regulations compliance route. Used for the building-regulations exemption page and for installer-vetting guidance in /warranty-aftercare. |
| Glass and Glazing Federation (GGF) | Trade body | GGF publishes consumer guidance on conservatory glazing standards, frame materials, and dispute resolution. Used for the glazing options page and for the dispute-route content in /warranty-aftercare. |
| UK Planning Portal | Government reference | Planning Portal published guidance on permitted development for conservatories under the Town and Country Planning (General Permitted Development) (England) Order 2015. The authoritative source for the /planning-permission page. |
Sources by category
For each cost band we draw from at least one source in each of the four categories below. This is the structural defence against the bias of any single publisher.
- Checkatrade
- MyJobQuote
- MyBuilder
- HouseholdQuotes
- FMB
- GGF
- FENSA
- DGCOS
- Which?
- Real Homes
- Homebuilding and Renovating
- Ideal Home
- Planning Portal
- gov.uk Approved Documents (Part L, K, P)
- Local Authority planning policy
Calculation method: by size
Floor area is the single largest driver of conservatory cost. The calculator uses a base £-per-m2 figure for each style and applies a small non-linear adjustment because installation cost does not scale linearly with size (groundwork, design, project management and warranty admin all have fixed components).
Indicative base uPVC £-per-m2 figures at 12m2 (4m x 3m) used as the calculator anchor: lean-to £900-£1,250, Edwardian £1,000-£1,400, Victorian £1,050-£1,500, gable £1,200-£1,700, P-shaped £1,000-£1,500 (weighted across the two zones), orangery £2,200-£3,500. These are derived from FMB rate guidance for the labour component (typically 35-45% of the total) plus aluminium / uPVC frame and glazing supplier pricing from FENSA-member installers.
Floor-area scaling: a 9m2 install runs roughly 12-15% per m2 higher than 12m2; a 20m2 install runs roughly 8-10% per m2 lower than 12m2. The calculator handles this internally; the published bands on each style page show the result at each size step (3x3, 4x3, 5x3, 5x4, 6x4).
Calculation method: by material
Frame material is the second-largest driver after size. Multipliers applied to the uPVC base:
- uPVC: baseline (~80% of UK installs). Lifespan 20-25 years.
- Aluminium: +35-50% on supply and install. Slimmer sightlines, 40+ year lifespan, suits modern homes and larger spans. Per Homebuilding and Renovating supplier surveys.
- Hardwood / oak / accoya: +90-130% on supply and install. Period-property look, 30-50 year lifespan with maintenance every 3-7 years. Per FMB hardwood-installer cost guidance and Real Homes hardwood-conservatory editorial data.
Calculation method: by region
The calculator applies a region multiplier on top of the base figure, derived from FMB regional labour-rate data and cross-checked against Checkatrade-published per-region average-job-cost data.
- London: +20-25% on the national baseline. Driven by higher installer day rates, smaller-site logistics overhead, and limited installer availability at peak season.
- South East: +10-15%. Similar drivers to London, less acute.
- South West and East of England: roughly at baseline (0% to +5%).
- Midlands: -5% to baseline. The reference region most published cost guides anchor to.
- North England: -5% to -10%. Lower installer day rates, comparable material costs.
- Scotland: -10% to -15%, with the caveat that planning is devolved and the GPDO 2015 thresholds do not apply. See /planning-permission for Scotland nuance.
- Wales: roughly -5% to baseline, with the planning differences noted on /planning-permission.
Calculation method: by roof type
Roof type is a binary cost driver for the comfort of the resulting space and a substantial cost driver for the build budget. The calculator treats polycarbonate as baseline (included in the style-base figure) and adds the upgrades:
- Polycarbonate: baseline. U-value ~2.8 W/m2K. Comfort range 6-10C in UK winter without heating.
- Glass with self-cleaning solar-control glazing: +£1,500 (3x3) to +£5,000 (5x4). U-value 1.0-1.4. Comfort range 10-14C unheated.
- Tiled warm roof (Guardian, Ultraroof, SupaLite): +£4,000 (3x3) to +£15,000 (5x4 and above). U-value 0.15-0.18. Comfort range 12-16C unheated. Note: triggers building regulations re-assessment in some scenarios per /building-regulations.
The roof-cost increments are taken from GGF guidance, FENSA member supplier pricing, and Anglian / Everest / Conservatory Outlet published replacement-roof price lists.
In scope
- Total installed cost: supply + build + base groundwork + electrics (Part P) + internal finish to plaster-ready or painted standard.
- Building regulations application fees where applicable (typically £400-£1,200).
- FENSA / GGF / DGCOS member installer rates as the assumed quote source.
- Region multipliers across the UK (London/SE, Midlands, North, Scotland, Wales).
- Style, size, material, glazing-spec and roof-type multipliers.
- Replacement-roof costs (polycarbonate-to-glass, polycarbonate-to-tiled, glass-to-tiled).
Out of scope
- Flooring (tile, engineered wood, vinyl, polished concrete) - budget £40-£140 per m2 separately.
- Furnishing, soft furnishings, blinds, curtains.
- Underfloor heating beyond the no-connection electric mat option (see /heating-insulation).
- Central-heating system extensions or new boiler capacity.
- Foundation work for sites with non-standard ground conditions (clay-shrink, made ground, sloping plot with retaining walls). Budget £500-£3,000 for ground-condition allowance.
- Planning application fees where required (typically £206 in England for a householder application). Excluded because most conservatories fall under permitted development.
- VAT on cost components where the supplier is non-VAT-registered.
- Specific named-installer rate cards. We publish bands; we do not publish "what Anglian charges for a 4x3 Edwardian" because that is a quote, not a published rate.
What we deliberately do not publish
- Specific named-installer rate cards. National installers redact specific quote pricing in writing. We publish band guidance, not named-firm specific quotes.
- Predictions of specific-quote outcomes. Calculator outputs are working bands. Actual quotes vary widely on local market conditions, plot access, base groundwork and installer order book.
- Personal homeowner data. Calculators run entirely in your browser. Your inputs are not transmitted, logged, or stored.
Update cadence
Site values update only when the underlying reality changes. Triggers:
- Material movement (10%+) in published installer day rates over a 12-month sample (per FMB regional data).
- GGF, FENSA or DGCOS published guidance change affecting consumer-facing band design.
- UK building regulations change affecting conservatory glazing or energy-efficiency requirements (Part L, Part K, Part P).
- Material change in float-glass / aluminium / uPVC commodity pricing visible in FENSA-member supplier price lists.
- Material change in UK planning policy (e.g. permitted development threshold changes, conservation-area policy changes).
Cosmetic date bumps are not made. The site-wide last-verified date reflects the most recent substantive review.
Limitations
Calculator outputs are working bands, not quotes. Actual installer quotes for the same brief will vary by 20-30% across three FMB / TrustMark / GGF-member installers on the same property. Drivers of variance the calculator cannot model:
- Site access (skip parking, machinery delivery, garden access constraints).
- Ground conditions discovered at survey stage (clay, made ground, services in the slab path).
- Installer order-book seasonality (peak season Apr-Sept adds 5-10% on premium installers).
- Specific glazing or hardware brand specification not captured in the multipliers.
The math behind every band is open. If the calculator produces a figure outside what your installer quotes are showing, that is signal worth digging into (either your installer is at the premium end, or the spec being quoted includes something not in our scope above).
Editorial position
This site is operated by Digital Signet, an independent AI-development studio. Digital Signet does not sell conservatories, does not act as a lead aggregator, does not run an installer-finder service, and does not accept paid placements from any conservatory installer or lead-broker. See /about for the operator and the wider network.
Editorial direction is set by Digital Signet's editor. Drafts are produced via Digital Signet's autonomous AI development methodology and reviewed against the editorial framework before publication.
Corrections
For methodology questions, factual corrections, or scenarios that don't fit cleanly: [email protected]. We aim to acknowledge within 5 UK business days and to publish or reject the correction within 10 business days.