Yes, a polycarbonate roof can be swapped for insulated panels while the frame stays put. We remove the sheets, fit 75 mm panels cut to your measurements, and roof heat loss drops by roughly 80 percent compared with 16 mm polycarbonate. Expect 1 to 2 days on site, with fitted prices from £3,000 that cover taking the old roof away.
Signs your polycarbonate has had its day
Lots of UK conservatories were built with polycarbonate because it was cheap and easy to lift. The sheet is plastic with twin, triple or multiwall chambers, and those trapped pockets of air are all the insulation it has. Years of sunlight wear down the outer face, and the faults usually show up in a cluster rather than one at a time.
- Discoloured, hazy sheets: clarity fades to a yellow tinge, and dirt in the flutes lets green or black mould take hold.
- Water coming in: the seals along each glazing bar harden and split, so rain finds its way in at the bars and where the roof meets the house.
- Sheets on the move: panels slide gradually towards the gutter, leaving a gap up at the ridge.
- Drips in winter: the underside is cold, so damp air from the room turns to water on it and falls.
- Drumming: a thin plastic skin turns every shower or hailstorm into a racket.
Recognise two or three of these? Then the covering is close to finished. To gauge how much life is left in yours, see our guide on how long a conservatory roof lasts.
What changes once the panels are on
Warmth that stays in the room
Take a 12 m² roof on a cold night, with 20°C indoors and 0°C outside. In 16 mm polycarbonate it sheds around 552 W, while our panels let about 103 W escape. Over an English heating season, if you keep the room heated, that works out at about 1,424 kWh a year falling to roughly 266 kWh.
A room you can sit in during July
Clear or opal, polycarbonate passes solar heat straight through, and that is why so many conservatories climb to 35 to 40°C on a sunny day. With an opaque insulated roof the sun no longer beats down through the top, so the space stops cooking in the afternoon.
Less noise, no drips
Because the inside skin of each panel sits near room temperature, condensation mostly disappears. The 75 mm foam layer also deadens the sound of rain, and customers tend to notice that the very first time it pours.
Is fresh polycarbonate a cheaper answer?
New sheets are an option. Re-sheeting a roof of 3 m by 3 m costs roughly £2,000 to £3,500 fitted. But brand new polycarbonate behaves just as your current roof did when it was installed: identical U-value, identical drumming and identical drips. In other words, the money buys back the same complaints.
| Current roof sheet | U-value (W/m²K) | Reduction in heat loss with Eco Tech panels |
|---|---|---|
| Polycarbonate, 16 mm | about 2.3 | roughly 80 percent |
| Polycarbonate, 25 mm | about 1.6 | roughly 73 percent |
| Polycarbonate, 35 mm | about 1.4 | roughly 69 percent |
| Eco Tech 75 mm panel | about 0.43 | not applicable |
We compare light, weight, sound and price in more detail in polycarbonate versus insulated roof panels.
Our fitting steps
- Dust sheets go down first. Then we remove the bar caps, the old sheets and the perished seals.
- We inspect the ridge, the gutter beam and each glazing bar, and we tell you about any damage before carrying on.
- Panels made to the sizes taken at survey are placed on the bars and held down under fresh caps and seals.
- We finish the ridge, hips and wall junction with trims, then clear the gutters or replace them.
- Your old polycarbonate leaves with us for recycling.
A panel is heavier than a polycarbonate sheet, which is why we never skip the frame inspection. Even so, the UK made panels we use are light enough for the majority of uPVC and aluminium frames, and our article on checking a frame for a solid roof lists what we assess. Plan on 1 day for a small lean-to or Edwardian, 1 to 2 days for a mid sized roof and 2 to 3 days for a large or P-shaped one, with no scaffold in most cases.
Price guide
A small roof starts at £3,000 fitted, a medium one at £4,000 and a large one at £5,000, and the usual spend sits between £3,000 and £7,500. Every figure covers removing the old covering, panels finished in your chosen colour, installation and the HomePro 10 year insurance backed warranty. Put in your roof size and style below to get a ballpark.
Common add-ons: £395 for each glazed roof light, £345 for LED spotlights and £295 for new gutters and fascia. You can see every line on our conservatory roof panel prices page, and finance through Kanda lets you spread the cost, subject to status.
Useful things to note before we visit
There is little to prepare, but a few details sharpen the quote. Jot down where water gets in and in which weather, and photograph any marks on the bars or the walls. Have any old paperwork ready, or a rough idea of the year the conservatory went up.
Tell us, too, what the room will be for. An office, a dining area and a children's den each need daylight in a different spot, so your plans guide where we put roof lights and spotlights.
Do I need planning permission?
Usually not, since the conservatory keeps the same footprint and height. If the house is listed, or the street is in a conservation area, National Landscape or national park, speak to the council before work starts.
Questions people ask
What lifespan should I expect from polycarbonate?
That depends on the sheet quality and how exposed it is to sun. Plenty of roofs put up in the 1990s and 2000s are now leaking, discoloured or slipping, and once the sheets and seals are failing together, a new roof normally works out cheaper than repairing it again and again.
Could you replace only some of the sheets with panels?
We seldom recommend it. The sheets left behind would keep losing heat and dripping, so nearly everyone has the whole roof covering done in one go.
My roof is 35 mm polycarbonate. Is replacing it still worthwhile?
If the room still feels cold or loud, yes. Against 35 mm sheets our panels reduce heat loss through the roof by roughly 69 percent, taking the U-value from about 1.4 to about 0.43.
What about glass instead of panels?
Glass is possible, and modern low-e roof glass manages 1.0 to 1.2 W/m²K. A glass roof measuring 3 m by 3 m runs to about £3,300 to £5,200 and the summer heat still pours in, so most homeowners now pick insulated panels.
Will Eco Tech remove the old polycarbonate?
Yes, every quote includes removal. We take the old sheets and caps off site and send them for recycling.
