If you are replacing a conservatory roof, the choice among glass, polycarbonate and a solid tiled system matters more than the brand or the colour. The three behave very differently once they are up: how much light they let in, how warm the room feels in January, how loud the rain is, how much weight the frame has to carry and whether the council needs to see drawings. Most of the regret we hear about conservatory roofs comes from picking on price or a showroom sample without asking how the room is actually used. This page sets the options side by side, in the order we would talk them through at a survey.
Start with how you use the room
The right roof starts with a plain question: what is the room for? A plant room, a dining space used every evening, a play area and a home office each need something different from the roof over it. A room used mostly in spring and summer for plants and morning coffee can live with a light covering. A room you want to sit in on a December evening, with the television on, needs a roof that holds heat and keeps noise down.
Next comes the aspect. A south or west facing conservatory takes the longest sun and will punish a clear roof, while a north facing room will be gloomy and cold under anything dense. Then there is the age and condition of the frame. A roof is carried by the frame, the dwarf walls and the foundations beneath them, and the heavier the roof, the more that structure has to prove it can take. All of that comes before cost.
Polycarbonate: light, cheap and easy to live with until you notice its limits
Polycarbonate is a rigid plastic sold in sheets with air channels inside, usually described as twin-wall or multi-wall. It is light, which makes it easy on the frame, and it is the covering most older and budget conservatories were built with. It is cheap to supply and quick to fit, and a sheet that is cracked or has failed seals can often be replaced individually.
Its weaknesses show up in use. The thermal performance is modest compared with other options, so a polycarbonate roof tends to be warm in summer sun and cold on winter nights. Rain on it is loud, because a thin plastic skin carries sound straight into the room. Over the years the sheets can yellow, scratch, grow algae in the channels and become brittle. The glazing bars and the closure strips at the edges need to be sealed well, or water finds its way in, and it is a frequent source of the leaks covered in our guide to leaking conservatory roofs. If you want to know how long to expect from one, see our answer on polycarbonate roof lifespan.
Polycarbonate suits a conservatory used lightly, on a tight budget, or one where you intend to change the room before long. It does not suit a space you want to use comfortably all year.
Glass: bright, quieter and warmer if you specify it well
A glass conservatory roof is made from sealed double glazed units, usually with a coating. The key details are in the specification. A self-cleaning coating reacts to daylight to break down dirt, a solar control coating cuts the heat that comes through in summer, and a low emissivity coating keeps warmth in during winter. Some units combine these, though what each coating does and what it costs varies by maker. Our answer on self-cleaning glass goes into whether that coating earns its price.
The strengths of glass are light and a clean look. The room stays bright, you can see the sky, and the roof ages well because glass does not yellow. It is much quieter in rain than polycarbonate, and a good unit is clearly warmer than a thin sheet. The cost is weight and price. Glass is heavier, which the frame must be able to carry, and it is more expensive to supply and fit, so the glazing bars and the frame need to be in sound condition.
Glass also does not answer the temperature problem entirely. Even a well specified glass roof loses more heat than an insulated solid roof, and in strong sun it lets a lot of light and warmth in. It is a good fit for a room where light matters most, such as a dining area or garden room you want to keep open to the sky. If your main complaint is comfort, our guide to curing a conservatory that overheats in summer and chills in winter will help you judge whether glass is enough.
Solid roofs: warm, quiet and a different kind of room
A solid conservatory roof replaces the translucent covering with a built-up roof: a lightweight tile or slate-effect surface on battens (timber laths that carry the tiles), insulation beneath, a vapour control layer, and a plasterboard or boarded ceiling inside. The best of these systems use a lightweight tile or composite panel so that the load on the frame stays manageable, and we explain how they work in lightweight tiled roof systems and the longer guide to tiled conservatory roofs.
The gains are big. An insulated solid roof holds heat in winter and keeps the sun out in summer, rain is far quieter, and the ceiling can take spotlights and a ceiling fan. In effect the room behaves like an extension. The losses are equally clear. It is darker, because the roof no longer lets light through, and you lose the view of the sky. Many owners add roof windows to bring some light back, a point we cover in roof windows in a solid conservatory roof, and our answer on whether a tiled roof makes a conservatory dark goes into how much difference to expect.
The paperwork is also different. A solid roof is classed differently from a glazed one: the council wants an application, because it has to be satisfied that the walls beneath will hold the extra weight. A registered or assured roof system can speed approval but does not remove the need for it. Our guides to conservatory roofs and Building Regulations and frame and foundation checks explain the process, and for planning questions check with your council's planning team.
The three side by side
The table below puts the main differences in one place. The descriptions are general, and the specification of the actual product changes the detail.
| Factor | Polycarbonate | Glass | Solid tiled |
|---|---|---|---|
| Light in the room | Good, can be dull if opal or tinted | Excellent | Limited, unless roof windows are added |
| Winter warmth | Modest | Better, especially with a low emissivity coating | Best, with proper insulation |
| Summer heat | Can overheat in strong sun | Depends on the solar control coating | Controlled well |
| Rain noise | Loud | Moderate | Quiet |
| Weight on the frame | Lightest | Heavier | Heaviest, needs a structural check |
| Building Regulations | Check with your building control body | Check with your building control body | Application needed |
Cost, and what drives it
We do not publish a price list, because the real cost depends on the size of the roof, its shape, the condition of the frame and whether the bars need replacing. What we can give is the one sourced figure we hold. One sourced typical UK range for a solid tiled conservatory roof is £6,100 to £15,000, roughly £650 to £1,200 for every square metre of roof, with the fixed quote coming only after we have surveyed. Our guide to conservatory roof replacement cost goes through what moves a price up or down. Glass and polycarbonate costs vary widely with the specification, so we quote those only once we have measured the roof.
It helps to look past the first price. A cheap roof that you replace again in ten years, or that leaves the room unusable for half the year, is not the cheaper roof. Equally, a solid roof is poor value if you wanted the sky and end up fitting four roof windows to get it back.
A few practical rules we give people
If light is your priority and the room faces north or east, glass is the stronger choice. If comfort in winter and quiet matter most, and you can live with a darker room, go solid. If the budget is tight or the room is a lightly used lean-to, a good multi-wall polycarbonate roof is respectable. If the roof is only leaking at the edges, ask whether repair would do before replacing anything, and see our answer on whether a conservatory roof can be repaired.
Some owners also ask about swapping plastic for glass without touching the frame, which is possible if the bars and frame can carry the glass. We cover this in replacing polycarbonate with glass.
Day-to-day living with each roof
The differences show up in small daily things. Under polycarbonate you hear every shower, you may find green algae creeping along the channels at the sheet ends, and the room can dim as the sheets age. Under glass the room stays bright all year, though the panes show bird droppings, pollen and leaf stains, so cleaning is a regular chore unless you choose a coated unit. Under a solid roof there is little to clean at the ceiling, but the tiles and gutters still need an occasional look, and moss can build on a shaded north-facing slope just as it does on a house.
Fitting also differs. A polycarbonate swap is quick and often finished in a day or two. Glass takes longer because the units are heavy and need careful lifting onto the bars. A solid roof is a small building project, with the old roof stripped, the new structure formed, and the ceiling and any roof windows finished. Our answer on how long a conservatory roof takes to replace sets out the steps in more detail.
Think, too, about what sits around the room. A conservatory under a tree collects leaf litter and sap on any roof, and the covering you choose should be easy to reach for cleaning. A room beside a neighbour's boundary may need a roof that does not reflect glare. A garden that slopes away from the house puts the roof at a harder angle for ladders. These are the practical details we note on the day, because they affect which covering will still look good in ten years.
How we help you decide
Our free survey looks at the frame, the foundations, the aspect and how the room meets the house. We photograph the existing roof, tell you plainly what condition it is in, and explain which of the three options fits and why. A fixed written quote follows, and we back the finished job with a ten-year guarantee on our workmanship, in writing. If a repair would serve you, we say so. You can book by phoning 01256 213956 or dropping us a WhatsApp message, or read about our full conservatory roof replacement in Basingstoke service.
