Glass covering.

Light transmission is yield — the covering decides it

The covering is the greenhouse's skin, and it makes a decision that echoes through the entire operation: how much light reaches the crop. Because within a crop's usable range roughly every extra percent of light returns an extra percent of yield, the transmission of the covering is not a detail but one of the most consequential choices in the whole design. What lets the light in is also what keeps the heat in and the weather out, so the covering has to balance transmission, insulation and durability against the local climate.

Glass remains the standard for the growing area, and for good reasons: it offers the highest light transmission of any covering and lasts for decades without clouding or degrading, so its optical performance holds up over the greenhouse's whole life. Within glass there are meaningful choices. Diffuse glass scatters direct sunlight so it penetrates deeper and more evenly into the canopy — lighting lower leaves that clear glass leaves in shade — while anti-reflective and other coatings can be applied to tune haze, boost transmission or add insulation, each measured against standards so different products can be compared objectively.

Glass is not the only answer, though, and matching material to purpose matters. Polycarbonate and insulated sandwich panels trade some light transmission for far greater impact resistance and thermal insulation, which makes them the sensible covering for service areas and side walls, and for climates with severe hail or extreme heating demands where a double-walled panel's insulation outweighs its lower light. Using glass where light is king and panels where robustness or insulation is king gets the best of both.

As with every other system, the right covering follows the climate profile rather than a fixed preference: the site's solar radiation, its heating costs and its exposure to hail or storm together point to the optimum specification for that location and crop. DutchGreenhouses® selects and combines the covering materials to maximise yield for your climate and budget. Get in touch to discuss the covering for your greenhouse.