Replacing a Conservatory Roof? Choosing Between Polycarbonate, Glass and Warm Roof Upgrades
If your conservatory is freezing in winter, unbearably hot in summer and/or annoyingly loud when it rains, the roof is usually the reason. Most UK conservatories were built to maximise light, not to control heat or sound, so they often end up feeling great for a few weeks a year and uncomfortable the rest of the time.
If you’re a homeowner thinking about replacing the conservatory roof, the main decision is simple: do you replace like-for-like and keep it feeling like a conservatory, or do you upgrade to make it usable for more of the year? Both routes can be worthwhile, but they deliver very different results - and suit different budgets.
Keep reading to get a grip on all the options, costs and regulations involved in replacing and/or upgrading your conservatory roof.
About planning permission and building regulations for conservatories
Can i DIY a conservatory roof replacement?
How much does a conservatory roof replacement cost?
How long does a replacement typically last?
Why is the conservatory roof so important for temperature and noise control?
The roof is the most exposed surface in a conservatory - it's important to understand how much of a role it plays because it affects everything else.
Uninsulated materials like polycarbonate and glass let a lot of light in but they can also let heat in and out very easily and can sound loud in the rain.
Windows and doors can matter too but the roof is the area that generally causes the most problems.
So when you're thinking about a roof replacement, you'll need to decide how important it is to try and make a real improvement in noise and temperature regulation. And then work out what can realistically be achieved within your budget (which is coming up below).
Conservatory roofs broadly fall into two categories:
-
See-through, uninuslated roofs – (primarily) the above-mentioned poly and glass options
-
Insulated roofs - sometimes called “warm roofs” but there are different types, they are often finished internally with a ceiling
Which one you’ll ultimately want will depend on your goal and budget.
A like-for-like replacement of polycarbonate sheets or glass is the best choice if maximum daylight is your primary need and your main current issue is an ageing roof (yellowing, leaks at the glazing bars, glare etc.). Both these options are popular and polycarbonate in particular is an excellent budget option that offers very good impact resistance.
The trade-off: neither of these options offer meaningful insulation for this intended use. So while replacing old or damaged panels may slightly improve things (i.e fixing the odd draught), the summer will still be hot, winter will still be cold, rain will still be loud.
Multiwall polycarbonate (a structured sheet with internal channels) is the most common polycarbonate conservatory roofing and choices include popular brands like Corotherm and Axiome. The sheets diffuse light, so the space usually feels a bit less harsh day-to-day.
If you choose multiwall, you’ll often find choices of twinwall, triplewall and sevenwall, which are basically the number of layers inside the sheet.
Which type of multiwall poly is best?
For a conservatory roof, you don’t really want to consider anything less than triple wall polycarbonate (around a 16mm thickness). Twin wall is just too thin and makes those too hot/too cold/too loud issues even worse (though thinner twinwall poly between 4mm - 10mm thick is usually ideal for greenhouses).
The more layers i.e if you choose sevenwall (usually around 25mm-30mm thickness), the more you’ll see a slight difference in noise and heat so if you want to stick with polycarbonate and want the most comfortable choice, this is the best option. But keep in mind this is still far from a properly insulated option - it will not control either noise or heat to any significant degree.
Sevenwall poly will also let slightly less light in vs the triplewall, it will have a slightly more opaque look which not everyone likes, so this will be a personal preference and/or budget choice (seven wall is naturally more expensive).
Solid polycarbonate (a single solid sheet) is a better choice if you want the clear glass look but with less weight, more impact resistance and a lower price (usually) than glass. But these are almost the only upsides and again, there will be no insulation properties.
Polycarbonate is also sold in different tints/finishes:
-
Clear: maximum daylight and sky view but most likely to create glare.
-
Opal: bright but diffused, usually the best choice for softer, more even light.
-
Bronze: reduces brightness and glare most, can make the space feel slightly more shaded.
Tints are usually quite widely available in multiwall varieties but not so much in solid.
Don't forget: if the roof framing parts like the glazing bars, end caps or gaskets (seals) are worn or distorted, you’ll need to replace those as well.
A glass roof is typically chosen for appearance and offers a more premium feel while staying fully see-through. As discussed above, typical, double-glazed standard glass won't offer any real temperature or noise control. Plus glass is still more at risk of shattering than polycarbonate and while for most homeowners not a huge risk, it's still something to keep in mind.
What about solar-control glass?
Solar-control glass - of the right spec and installed correctly - can genuinely make a conservatory noticeably less prone to “greenhouse” overheating. This is because it’s specified to reduce the amount of the sun’s energy that passes through the glazing. You’ll still get plenty of light (though it might be a little less) but less solar heat gets through. This reduction is commonly measured as a “g-value” - lower being better or more reduction of sun radiation.
It still won’t make the space behave like a solid insulated room - you would still have a largely glazed roof. But in a sunny, south/west-facing conservatory it can be the difference between unusable in strong sun and maybe kind-of manageable with fans and blinds.
Will blinds, ventilation and heaters make my conservatory more usable year-round if i have an uninsulated roof?
Not really. The solar glazing just discussed may help a bit in summer but won’t offer any significant benefit in winter besides basic double glazing properties. Heaters can certainly help in the winter but the roof will still lose heat quickly.
Blinds, fans and ventilation may take a little edge off in summer and this might be enough. For some conservatory owners, maximum daylight is critical and they're happy to use these extras to try and keep the space usable.
But if comfort is your main goal, the only thing that will offer a truly meaningful difference in temperature and noise is an insulated roof option.
Keep reading for more.
You need a conservatory roof solution that includes insulation.
If you’ve had enough of overheating in summer, freezing in winter and loud rain noise, this is the direction that changes how the room behaves day-to-day. The common trade-off is you lose the full “sky roof” though the side glazing still keeps the room bright and there are options to add rooflights.
These are the most common types of insulated conservatory roofs:
What it is: insulated panels (or insulation plus internal panels) fitted under your current polycarbonate/glass roof.
Realistic improvement: a clear drop in the “sun beating down” feeling and a noticeable reduction in rain drumming. Winter comfort usually improves too, but the space still won’t behave like a fully insulated room. This is the best budget option where comfort is more important than light.
Limitations: it’s only internal, so it won’t fix leaks or failing old seals or panels, you’ll still need to replace those too if they’re causing issues.
Option B: insulated replacement roof panels swapped into the existing frame (mid-budget)
What it is: the existing roof glazing is removed and replaced with solid insulated panels made to fit the current conservatory roof framework (panel finish externally).
Realistic improvement: typically a bigger jump than Option A for both temperature swings and rain noise, because the glazed roof surface is replaced with an insulated one.
Limitations: generally no roof transparency (unless the system offers dedicated glazed modules) and you’re still constrained by the existing frame layout.
Option C: full warm roof conversion (highest budget, most “final” result)
What it is: the old roof is removed and replaced with a complete roof system (new structure + continuous insulation + internal ceiling), usually finished in panels or lightweight tiles.
Realistic improvement: the most room-like outcome - usually the best temperature stability and the quietest result, because it’s a complete insulated roof build-up with the most flexible detailing. Also the installation that can give the most "extension-like" appearance. This is due to the ability to finish externally with synthetic tiles, like Britmet's artificial slates, that can match or get close to matching the main house roof tiles.
Limitations: most disruption, longest install and most likely to need Building Regulations sign-off when switching from a translucent roof to an opaque one. The regulations part is usually handled by the provider see more details in: Planning permission and Building Regs below.
If your only hesitation about going to a solid rood is “it’ll feel too dark”, rooflights/roof windows are how you keep daylight from above while still getting the comfort benefits of an insulated roof.
The best of both worlds:
-
keeps the room feeling lighter and more open than a fully solid ceiling
-
preserves some of the conservatory feel without giving up the comfort upgrade
-
especially useful if the conservatory is north-facing or already shaded
Practical note (for quoting)
Rooflights/roof windows are best planned in from the start (position, size and how they sit within the roof), so raise the idea early when getting quotes.
Rules vary by property type, location and the specific nature of the upgrade. While this is not legal advice, understanding the regulatory requirements is vital to ensuring your home remains safe and legally compliant for a future sale.
Do I need planning permission for a conservatory roof change?
In many cases, changing a conservatory roof doesn’t trigger planning issues if the footprint of the building remains the same. However, the usual kinds of exceptions apply for:
• Listed buildings or properties in conservation areas.
• Unusual design constraints or significant structural alterations.
• Properties with restricted development rights.
If you have any doubt, checking with your local authority is normally straightforward and highly recommended.
Building Regulations and the "solid roof" rule
You may not need planning permission, but under UK rules, changing a conservatory roof from translucent (glass or polycarbonate) to opaque (a solid insulated roof, including lightweight tiles or solid panels) will usually bring Building Regulations into play.
In practical terms, the upgraded roof needs to meet requirements around structural safety and thermal performance, and you’ll typically want the completion certificate for your records (and for future house sales).
The good news is that installers who specialise in warm roof conversions or insulated panel replacements will usually handle the Building Control route as part of the job. That normally includes the site survey/structural assessment needed to confirm the existing conservatory can support the new roof system. Just make sure the quote is clear on what’s included and what certificate you’ll receive at the end.
If you’re only adding internal insulation under the existing roof, Building Regulations may not apply in the same way - but it can depend on what’s being changed and how the conservatory connects to the main house.
Either way, raise it early when gathering quotes. A reputable installer should be able to explain it clearly and include it in writing if it applies.
The only realistic option for most non-trades or non-roofing specialists is a like-for-like polycarbonate replacement. A DIY job might be practical if:
- you’re replacing a similar system
- the frame, bars and seals are in good condition
- you’re confident measuring accurately and handling large sheets safely
As discussed above, most other replacment types are going to require at least the partial if not full help of specialists - see rough costs next.
How much does a conservatory roof replacement cost?
The numbers below are intended as a rough guide to help you compare the different routes in relation to each other.
Individual quotes can vary significantly depending on the size and shape of the conservatory, access/scaffolding, your location, the spec you choose (sheet thickness/tints, glazing performance, rooflight sizes) and the condition of the existing frame/bars/seals.
|
Option |
Rough pricing (UK, supplied + installed unless stated) |
|
1) Polycarbonate roof sheets (DIY supply-only) |
£400–£1,800 |
|
2) Polycarbonate roof sheets (replacement + install) |
£2,500–£4,000+ |
|
3) Glass roof (standard double glazed) |
£3,000–£8,000+ |
|
4) Glass roof (solar-control glazing spec) |
£3,500–£9,000+ |
|
5) Internal roof insulation only (ceiling under existing roof) |
£2,000–£4,500+ |
|
6) Insulated panel replacement (swap glazing for solid insulated panels) |
£3,000–£6,500+ |
|
7) Full warm roof conversion (lightweight tiles) |
£6,500–£15,000+ |
|
8) Warm roof conversion + rooflights/roof windows |
£8,000–£18,000+ |
Polycarbonate is the easiest like-for-like budget replacement that'll give lots of light while the internal cladding route is a good budget option where temperature control is more important.
If budget can stretch, a full warm roof with panel or tile finishing is usually the route that'll get the best overall insulation results and give the most natural "extension-looking" aesthetic.
When you're considering costs, it's also worth keeping in mind the average lifespan of these options as this also matters for ultimate value for money.
Average lifespan of different conservatory roof replacement materials and types
Again, these numbers are a rough guide and actual performance may be affected by different variables:
|
Option |
Average lifespan (typical) |
|
1) Polycarbonate roof sheets (multiwall) |
10–20 years |
|
2) Polycarbonate roof sheets (solid) |
20–25 years |
|
3) Glass roof (standard double glazed) |
15–30 years |
|
4) Glass roof (solar-control glazing spec) |
15–30 years |
|
5) Internal roof insulation only (ceiling under existing roof) |
10–20 years |
|
6) Insulated panel replacement (swap glazing for solid insulated panels) |
15–30 years |
|
7) Full warm roof conversion (lightweight tiles) |
30–50 years |
|
8) Warm roof conversion + rooflights/roof windows |
30–50 years (roof) / 15–30 years (rooflights) |
Where to next?
Choosing a new conservatory roof can feel like a bit of a job in itself but once you understand the basic options you'll be able to get to the next step more easily.
If you're looking for high-quality polycarbonate for a budget upgrade or insulation or synthetic lightweight tile roofing to complete your warm roof conversion, we're here to help! Or if you just want to generally discuss all the conservatory roofing options, give our customer service team a call and they'll be happy to help.
Or explore more articles and products below.
