Most conservatory complaints come down to one thing: the roof. Too hot in summer, too cold in winter, and the room ends up as storage nine months of the year. The frames and glazing matter, but the roof decides whether the customer actually uses the space. Three options cover the market — a solid warm roof, glass, and polycarbonate — and the gap between them is bigger than customers expect.
The short answer
Fit a solid warm roof when the customer wants a room they use all year — it's the biggest upgrade in comfort. Fit glass when they want light and views with good year-round performance. Only fit polycarbonate as a budget or lightweight option where all-year comfort isn't the priority.
Polycarbonate — the budget baseline
Polycarbonate is the lightweight, low-cost multi-wall sheet that topped most older conservatories. Its strengths are price and weight: it's cheap and light enough for slim frames. Its weaknesses are exactly why those conservatories go unused — poor insulation, so the room bakes in summer and chills in winter, and it's noisy in rain to the point of drowning out conversation. It still has a place on a porch, a lean-to or a tight budget, but for a room the customer wants to live in, it's the weakest choice.
Glass — light and performance
A modern glass roof uses sealed, coated units — typically self-cleaning on top and solar-control coated to cut summer heat gain, with a low-e coating to hold warmth in winter. You keep the light and the open, airy feel of a conservatory while getting genuinely usable year-round temperatures and near-silent performance in rain. It costs more than polycarbonate and adds weight (so the structure has to suit it), but for most customers who want a bright garden room it's the sweet spot.
Solid warm roof — the comfort upgrade
A solid (or "warm") roof replaces the glazed roof with an insulated, tiled or slated structure — effectively turning the conservatory into an extension. It's the best thermal performer by a distance, achieving low U-values that make the room genuinely comfortable in a heatwave and a cold snap alike, and it's the quietest in rain. You lose the fully glazed sky, but most systems let you set in roof windows or an internal pergola with downlights to keep light and a finished ceiling. This is the go-to for turning a cold, unused conservatory into a room the customer treats as part of the house.
| Solid warm roof | Glass | Polycarbonate | |
|---|---|---|---|
| All-year comfort | Best | Good | Poor |
| Natural light | Via roof windows | Excellent | Good |
| Noise in rain | Silent | Very quiet | Loud |
| Weight | Heaviest | Heavy | Lightest |
| Relative cost | Highest | Mid | Lowest |
The structural check — don't skip it
Weight is the practical catch. Swapping an old polycarbonate roof for glass or a warm roof adds load the existing frames and base were never designed for, so the structure has to be assessed before you commit. A good warm-roof system is engineered to spread the load and many are designed to drop onto existing conservatory frames — but that's a check to make on survey, not an assumption. Get it confirmed and the upgrade is straightforward; skip it and you're storing up a problem.
Building Regs
Replacing a like-for-like conservatory roof is usually straightforward, but a solid roof can move a conservatory closer to being treated as an extension, which can bring thermal and structural requirements into play. It's worth checking the position on solid-roof conversions early so the customer knows where they stand.
How to steer the conversation
- "We never use it — too hot and too cold": solid warm roof.
- Wants light and views, used most of the year: glass.
- Budget-led, porch or lean-to: polycarbonate.
- Hates the noise in rain: warm roof, or glass as a step up from poly.
- Always: confirm the structure can take the weight before quoting glass or solid.
We supply solid warm roof systems alongside full glazed conservatories, so whether the job is a new build or a roof upgrade on an existing frame, you can offer the customer the right roof for how they actually want to use the room — and get it all from one supplier.
