The glazing decides more about your greenhouse than the frame does. It sets how much light your plants get, how warm the greenhouse stays at night and how safe it is around children. There are three main choices.
Horticultural glass
The classic choice on Halls and Vitavia greenhouses, usually 3 mm thick and fitted in small panes.
- For: lets in the most light, stays clear for decades, cheapest glass option.
- Against: breaks into sharp shards. A football or a falling branch leaves a dangerous mess. Single glass keeps little heat in at night.
Toughened glass
Toughened (safety) glass is heated and cooled in a way that makes it several times stronger. If it does break, it falls into small blunt pieces instead of shards.
- For: same light as horticultural glass, much safer, often in larger panes that look cleaner.
- Against: costs more and weighs more, so the frame and base have to be sturdy.
If you have children or pets, or the greenhouse stands near a path or a lawn, choose toughened glass. Our score gives toughened glass 1.5 points and horticultural glass 1 point for that reason.
Polycarbonate
Polycarbonate is a plastic that is very hard to break. It comes as clear single-wall sheets or as twinwall panels with hollow channels inside.
- For: light, hard to break, twinwall panels insulate better than single glass. A good choice for windy sites and for families.
- Against: twinwall panels are not see-through, they diffuse the light. Polycarbonate scratches more easily than glass and can lose clarity over the years.
Palram Canopia uses polycarbonate throughout its range. Some models, such as the Hybrid, mix clear single-wall sides with a twinwall roof. Palram's frame guarantee does not cover the polycarbonate itself. More on panel thickness in our guide to twinwall polycarbonate.
Which is right for you?
| You want | Choose |
|---|---|
| The most light, and a classic look | Glass |
| Safety near children and ball games | Toughened glass or polycarbonate |
| Warmth in spring and autumn | Twinwall polycarbonate |
| The lowest price | Horticultural glass or single-wall polycarbonate |
| A windy, exposed garden | Polycarbonate on a well anchored base |
Diffused light from twinwall panels is not a problem for most plants. It spreads the light and lowers the risk of scorch in summer. For tender plants over winter, twinwall polycarbonate keeps more warmth in than single glass, and a glass house needs bubble insulation to match it.
Browse the options under polycarbonate greenhouses and glass greenhouses.
