A glass conservatory roof today is a very different product from the one that gave conservatories their reputation as too hot in summer and too cold in winter. Coated, insulated glazing units with solar control have changed the comfort substantially, and for people who want to keep the light, glass rather than a solid roof is often the right upgrade.
What the coatings do
Modern roof glass carries two coatings doing opposite jobs. A low emissivity coating reflects heat back into the room in winter, cutting the heat loss that made old conservatories unusable in January. A solar control coating reflects a proportion of incoming solar energy in summer, which is what stops the room becoming unbearable in July. Self cleaning coatings on the outer face break down organic dirt and let rain sheet it off, which matters on a surface nobody can reach safely.
Conservatory roof glass replacement: the panels rather than the roof
Where the frame and the glazing bars are sound and it is the glass that has failed, misted, or is simply old plain glass, the panels alone can often be replaced within the existing structure. That is far cheaper than a new roof and is frequently the right answer on a conservatory whose frame is in good condition. It is worth asking about before accepting a quote for a complete replacement roof.
A glass conservatory roof replacement against a solid roof
Glass keeps the light, which is the reason most conservatories were built. A solid roof gives better insulation, much less noise in rain, and no overheating, at the cost of daylight. A glazed roof with good coatings sits between the two and costs less than a solid conversion on many jobs. Where the room faces north, glass loses less of its advantage; where it faces south and west with nothing shading it, solar control glass is not optional.
Weight, safety glass and a lean to conservatory glass roof abutment
Roof glazing is overhead glazing, so the inner pane is normally laminated so that a failure does not drop glass into the room, and Approved Document K is where that expectation sits. A glazed roof is heavier than polycarbonate, so the frame check applies here too even though it is less dramatic than a tiled conversion. On a lean to, everything depends on the abutment detail where the roof meets the house wall: the flashing and the box gutter there are the most common leak on any conservatory.
Replacement conservatory glass: roof panels and side panes are different jobs
A misted or cracked pane in a conservatory side frame is ordinary double glazing work and a local glazier can usually replace the sealed unit in the existing frame. A roof panel is not: roof glazing is normally a laminated or toughened unit in a bar system, it is heavier, it is worked at height over a room you cannot easily protect, and on many systems the glazing bars and gaskets have to come apart to get it out. Ask which of the two you have before you call, because the trades and the prices are different, and a firm that quotes a roof panel at side pane money has not seen it.
Questions people ask about glass conservatory roofs
Is a glass conservatory roof still too hot in summer?
Much less so with solar control glass than with the plain glass or polycarbonate that gave conservatories their reputation. A south or west facing room with no shading will still warm up, and ventilation and blinds still earn their place.
Can I replace just the glass panels?
Often yes, where the frame and glazing bars are sound. It is substantially cheaper than a new roof and worth asking about explicitly.
Is self cleaning glass worth it on a roof?
On a surface nobody can safely reach, yes, more than anywhere else on the house. It reduces rather than eliminates cleaning.
Does a glass roof need building regulations approval?
Replacing like for like on an exempt conservatory often does not. Changing the roof type or the structure can, so confirm with the installer which they are doing.