Which Conservatory Insulation Panel to Buy
Four different products are sold under one phrase, and only two of them have a published price. None of them has a published U-value as fitted, which matters because the number on the box is not the number your roof gets.
Rigid insulation board · per square metre · supply only · inc VAT
£15 to £40/m² multifoil £10 to £20/m²
Thin evidenceOne publisher, 2 July 2026. Checked 20 August 2026.
What conservatory insulation panels cost, and why that is a supply-only number
Rigid PIR or XPS insulation board is £15 to £40 per square metre and multifoil is £10 to £20 per square metre, both supply only, including VAT. Thin evidence: one publisher, 2 July 2026, checked 20 August 2026. Those are the only two panel prices published anywhere in the UK market, and they are material rates. They do not include the frame that holds the panels, the finish underneath them, or anybody's labour.
| Product | Rate, supply only | Evidence | Sources |
|---|---|---|---|
| PIR or XPS rigid board | £15 to £40/m² | Thin | One UK cost publisher, 2 July 2026 |
| Multifoil quilt | £10 to £20/m² | Thin | One UK cost publisher, 2 July 2026 |
| Interlocking aluminium or uPVC ceiling panel | no supply-only rate published | Gap | Priced only as a fitted ceiling finish |
| Proprietary insulated roof panel system | no price published | Gap | Quote only, see below |
Source: one UK cost publisher, 2 July 2026, for both priced rows. A single publisher stands behind every insulation figure on this site, which is why nothing here is graded above Thin and why the caveat repeats on every table rather than sitting once in a footnote. Note that the source prices PIR and XPS as one line, so we do not split them: nobody publishes a separate rate for each. Checked 20 August 2026, next check due 20 November 2026.
The supply-only distinction is the one that decides whether a price is useful to you. At the rate above, nine square metres of multifoil is under £200 of material, and nine square metres of finished insulated ceiling is four figures. Both numbers are true and they answer different questions. The whole family of methods, priced against each other, is the cost of insulating a conservatory.
The four things sold as conservatory insulation panels
They sit in different places in the build-up and they are not alternatives to each other in the way the advertising implies.
- Multifoil quilt. Layers of foil and wadding, stapled or friction-fitted between the glazing bars or above a new frame. Thin, light, easy to handle overhead, and it needs an air gap on at least one face to do anything at all. £10 to £20 per square metre, supply only.
- PIR or XPS rigid board. Foam board, cut to fit between members. Thicker, stiffer, and the thing most trade installers actually use above a suspended frame. £15 to £40 per square metre, supply only.
- Interlocking aluminium or uPVC ceiling panel. Not insulation. This is the finished surface you see from below, clipping into the frame with the insulation hidden above it. It is sold as a panel and priced as a ceiling, which is where most of the confusion in this category comes from.
- Proprietary insulated roof panel system. A composite board with a factory-applied finish, sold under trade names, usually through a dealer network and usually with the price behind a form. These are the products marketed as thermal or thermo panels, and we have no verified price for any of them.
Both material rates above: Thin evidence, one publisher, 2 July 2026, checked 20 August 2026.
Two of those four are insulation, one is a finish, and one is both. A quotation that says “insulated panels” and nothing else has told you which layer it is pricing in exactly none of the four cases, so ask which of these it means before you compare it with anything.
Panels against a ceiling: what the installed prices actually price
There is no installed price for a panel type anywhere in UK public data. Nobody publishes what a PIR job costs against a multifoil job. What does exist is priced by ceiling finish, and the rows below are those, relabelled honestly. They tell you what the visible surface costs, not what the insulation behind it costs.
| Finish | Per m², fitted | 3m × 3m total | Evidence |
|---|---|---|---|
| Aluminium panel | £85 to £160 | £1,050 to £1,200 | Thin |
| uPVC | £95 to £180 | £1,200 to £1,450 | Thin |
| Plastered | £145 to £275 | £2,200 to £2,750 | Thin |
| Any of the above, by panel material | no publisher separates the price by what is above the finish | Gap | |
Source: a single UK cost publisher, 2 July 2026, Thin evidence on every row. Prices installed and including VAT. Checked 20 August 2026. These are ceiling finish rates and they are reproduced here for context, not as panel prices. The job itself, and how the frame goes up, is conservatory ceiling insulation.
The practical consequence is worth stating plainly. Read down that table and the spread at 3m × 3m is a thousand pounds or more, and all of it is the visible surface: plaster against aluminium on the underside, rather than a better or worse insulant above it. Ask what is going in above the finish, in millimetres and by product name, and you will usually be the first person to ask.
U-values by panel type, and the ones nobody publishes
The title of this page promises U-values, so here is the honest version of that table, including the rows that are empty.
| Element | U-value, W/m²K | Evidence | Named source |
|---|---|---|---|
| Multifoil quilt, as fitted in a conservatory roof | no published figure | Gap | No publisher and no supplier states one |
| PIR or XPS board, as fitted in a conservatory roof | no published figure | Gap | No publisher and no supplier states one |
| A finished insulated conservatory ceiling | no published figure | Gap | No publisher and no manufacturer states one |
| The polycarbonate roof left above the panels | 0.83 to 3.2 | Well | Brett Martin, Palram, Arla Plast and Ultraframe technical data |
| Solid roof systems, across eight named systems | 0.10 to 0.18 | Well | Eight manufacturer system datasheets |
| Roof in an existing dwelling, limiting value | 0.15 | Well | Approved Document L Vol 1, 2021 with 2023 amendments, Table 4.2 |
| Rooflight, limiting value | 2.2 | Well | Approved Document L Vol 1, Table 4.2 |
Sources: manufacturer technical literature for the polycarbonate band and the solid roof systems; Approved Document L Volume 1, 2021 incorporating the 2023 amendments, Table 4.2, for the limiting values. Retrieved and checked 20 August 2026. Zero of the thirteen competing pages we surveyed publish any W/m²K figure at all, which is why the first three rows are gaps rather than numbers we could borrow from a neighbouring product.
The U-value depends on the number of walls, not the thickness. Two 16 mm polycarbonate sheets can differ by 0.6 W/m²K: triplewall is 2.4 and sevenwall is 1.78. A 10 mm twinwall is 3.2 and a 55 mm tenwall is 0.83. Anyone quoting you a single U-value against a millimetre figure alone is quoting a number that does not exist. Verified against Brett Martin, Palram, Arla Plast and Ultraframe technical data, checked 20 August 2026.
The bottom half of the table is the argument for the whole category, and it is also its limit. Even the best polycarbonate on the UK market is more than five times the limiting value that a replacement roof has to reach, so putting insulation underneath it is worth doing. But no combination of panels under an existing translucent roof reaches 0.15 W/m²K, none of it makes the conservatory a habitable room, and nobody can honestly certify it. What the standard actually asks is conservatory roof U-values and Part L, and the words in this section are defined in the glossary.
The systems with no published price at all
Two named panel products come up repeatedly in this market and neither publishes a figure we can stand behind. We would rather name the hole than fill it with something from a neighbouring product.
- Green Space insulated panels. The company publishes no system-specific price. What it does publish, verbatim, is that its panels are “usually in the same price bracket as tiled roofing”, which points you at a different product entirely and is the closest thing to a figure on the site. Verified negative, checked 20 August 2026.
- Thermotec. One dealer's pricing page is password protected and another dealer's carries no figures at all, so we publish no number for it. What would close the gap: one dealer quotation with the specification attached. Unverified, checked 20 August 2026.
This is worth knowing before a sales visit rather than after one. A product with no published price is not necessarily expensive, but it is a product you cannot benchmark, and the only defence is to get the specification in writing and price the alternatives at the same time.
Fitting them yourself, and what that changes
What a supply-only price buys
- The insulation material, cut or rolled, and nothing else
- No frame, no battens, no fixings
- No finished surface underneath
- No labour, which is 65% to 75% of a fitted job
What it does not buy
- Any ventilation of the void the panels create above them
- Reinstated electrics or new lighting
- Decoration once a plastered finish has dried
- A certificate, because this work is not notifiable
Labour at 65% to 75% of the total is Thin evidence, one publisher, 2 July 2026, checked 20 August 2026, and it is the number that explains why a material rate and a fitted rate are an order of magnitude apart. Whether the saving is real at your size, and where the crossover sits, is conservatory roof insulation diy.
Price the roof, not just the panel
Six questions, roof condition first, phone number last. They live on the calculator, not on this page.
A panel price only means something next to the price of the roof it is going under. Get both figures on the same day and the choice makes itself.
Or get conservatory roof quotes and ask each installer to name the panel product and its thickness in writing.
Check what your roof will cost, or compare local conservatory roof installers. We pass your details to vetted installers so they can quote, and we are paid when they do. how we make money.
The other ways the same roof gets covered
Panels are one answer to a cold conservatory and they are the cheapest one that involves buying anything. The nearest neighbour is cladding a conservatory roof, which is the same family of products sold as a surface rather than as an insulant, and it runs into the same gap: no publisher prices it as a product either.
At the other end, a tiled or solid roof at 3m × 3m is £6,000 to £11,000 installed including VAT. Well evidenced, four publishers agreeing within 1.05x on the floor, checked 20 August 2026. That is five to six times a panelled ceiling and it buys a different thing: a structure that reaches 0.15 W/m²K, goes to building control, and works in July as well as February. The case for it is solid roof conservatory cost, and the full range by size and material is conservatory roof replacement.
Questions people ask first
How much are insulated panels for a conservatory roof?
Which is better, multifoil or rigid board?
What U-value will insulated panels give my roof?
Are thermal panels worth it over ordinary board?
Do panels stop condensation, or cause it?
Do insulated panels need building regulations approval?
Every figure on this page was last checked 20 August 2026, next check due 20 November 2026. Every price row rests on a single publisher, stated on each table rather than buried here. To compare a panelled ceiling against a new roof, use our conservatory cost calculator.
Find out what yours costs
Six questions, about sixty seconds, and an estimate built from published UK figures with every source shown. Then up to four local installers can quote you, if you want them to.