There are two types of roof glazing for diy self build conservatories. The cheaper option is polycarbonate, which is provided with your DIY conservatory in the form of a 25mm, five wall structure. This comes in clear, opal and bronze. The upgrades from the standard are bronze on opal and heat guard. The upgrade from the 25mm, five wall system is the 35mm seven wall system. This has better insulation and heat reflective properties due to the extra layers that heat has to pass through. The 35mm system comes in the same finishes as the 25mm system, using the same upgrades.
The alternative and more expensive glazing option are double glazed sealed units. An untreated unit does not have very good insulation properties but compared to poly it is 100% quieter in the rain. Treatments to the unit start with a low-e coating that improves the U-value. When argon is added to the unit the insulation values increase further. A heat guard treatment reduces solar heat gain and glare. The top of the range treatment is Celsius Elite, while being expensive, it is the most effective diy conservatory roof glazing system.