The short answer
Most of a conservatory's summer heat comes through the roof, which lets the sun in and traps the warmth. A solid or insulated roof cuts that gain, a solar-control or self-cleaning glass roof reduces it, and vents and blinds take care of what remains. The right option turns on your use of the room and the strength of the frame.
Where the heat comes from
Sunlight passes through clear glazing as short-wave radiation, warms the floor, furniture and walls, and is then re-emitted as heat that cannot easily escape back through the glass. The roof does most of the work because it faces the sky for most of the day and is the largest single area exposed to the sun.
An older polycarbonate roof is often the worst offender. Thin twin-wall sheets give little protection, and the material loses performance as it yellows and clouds. The room can be uncomfortably hot by mid-morning, and the effect is stronger on a south or west-facing house. The glass walls add to the gain, but fixing the roof usually brings the biggest improvement.
The other half of the problem is that hot air rises and collects at the top. Without a way out, it stays there. Our page on conservatory roof vents shows how releasing it at the high point helps.
Roof options compared for overheating
Each roof type handles the sun differently.
| Roof type | What it does for summer heat |
|---|---|
| Standard polycarbonate | Offers little resistance to heat gain; opal or tinted versions help a little |
| Solar-control glass | Has a coating that reflects part of the sun's energy while still letting light through |
| Self-cleaning glass | Keeps the surface clear, and may have a solar-control layer; check the specification |
| Solid or tiled roof | Blocks direct sun and holds insulation, so the room stays far more stable |
A solid or lightweight tiled roof gives the biggest change in temperature, but it also makes the room darker and costs more. Our page on lightweight tiled roofs looks at what is involved, and the guide to self-cleaning glass explains what that coating does and does not do.
Costs and what the structure will take
MyBuilder's conservatory roof guide, updated in August 2026, gives national typical ranges: polycarbonate at £2,000 to £5,000, glass at £3,000 to £8,000 and solid at £5,000 to £10,000, with structural reinforcement of £500 to £2,000 where needed. They are guide figures from a third party. Your own number comes only from the quote that follows a look at the roof.
The frame decides the options. In the words of Homebuilding & Renovating, solid roofs count as material alteration work, which brings a building control application into the project, and old frames then support extra weight. If your frame dates from the polycarbonate era, expect the survey to ask whether strengthening is needed before tiles can go on. That can add to the quote, which is why the frame deserves a look before you choose. Our page on lean-to conservatory roofs and the one on Victorian conservatory roofs show how the shape alters what can be done.
Cheaper steps to try first
Replacing the roof is not always the answer. Several smaller changes reduce heat and may be enough, particularly if the roof is still in good order.
- External shading. A shade outside the glass stops the sun before it enters the room, which works better than a blind inside.
- Internal blinds. Reflective blinds help, especially roof blinds fitted close to the glass. The page on conservatory roof blinds compares types.
- Opening vents and doors. Moving air removes heat that radiation has added.
- Solar-control film. A film on existing glass reduces gain, though it does not suit every glazing type.
A roof that is sound, and a room that is only hot for a few weeks, is a good candidate for these. A roof that leaks, has cracked sheets or is worn out is a stronger case for replacement. Polycarbonate roofs are quoted as lasting around 10 to 15 years, so the age of yours is part of the decision. If yours is past that age and still overheats, replacing it beats shading it.
A solid roof is a trade-off
A solid roof makes the room more like an extension. It stays cooler in summer and warmer in winter, and it can be used all year. It also loses the sky view and the open feeling that attracted you to a conservatory in the first place. Adding roof windows or rooflights brings daylight back, as our page on skylights in a solid conservatory roof explains.
The thermal side is regulated as well. Part L of the Building Regulations limits heat loss through new roof parts in an existing home, with its own figures for roof windows and for rooflights. The design is therefore settled before the roof is ordered, not afterwards. The building control body checks the result.
Telling your insurer and choosing a roofer
A change of roof type is worth reporting, since it alters what the policy covers. Our page on telling your insurer about a conservatory roof lists what to ask. For how a project runs from survey to finish, see the conservatory roof process.
At the survey we check which way the room faces, how it is used, what the frame can take and how it is ventilated now. Our quote is written, it carries pictures of your own roof, and the job we put forward is the lightest one that cures the heat. That could be a blind and a vent, a glass upgrade or a full solid roof. Our workmanship guarantee runs for 10 years, in writing. The hub page on conservatory roof replacement covers the options in more detail.