Sustainable Modular Underground Greenhouse System:
this is an underground greenhouse system. The advantage of the subterranean design lies in the use of the earth‘s natural thermal storage properties, which allows for maintaining cooler interior temperatures year-round—without the need for energy-intensive air conditioning—at a level that supports optimal plant growth.
This design consists cost-efficient octagonal modules arranged in a flexible and modular layout. The number and positioning of modules can be adapted to suit nearly any type of property.
exemplary array of 9 greenhouse units in a desert area
Client: Aya Kenz / Dubai
The walls are constructed solely from earthbags, following the Hyper-Adobe system. In this method, walls are built layer by layer using tubular mesh sleeves filled with locally excavated soil. The cylindrical shape of the walls ensures high resistance to soil pressure.
Both the floor and the earthbag walls are enclosed in a membrane, which serves two purposes: it prevents insects and saline groundwater from entering, and it also keeps internal moisture from seeping into the dry surrounding soil.
exemplary array of 9 greenhouse units floor plan
exemplary array of 9 greenhouse units, x-ray axonometric view
The cylindrical walls are capped with a modular octagonal steel frame, over which a membrane is stretched. This design prevents any water loss from the greenhouse: water vapor condenses on the ceiling membrane and drips back down into the substrate layer.
The ceiling membrane is partially made of transparent ETFE foil and partially of reflective foil. This combination ensures that only the optimal amount of light required for photosynthesis enters the space—avoiding excess light that could otherwise lead to overheating.
Across the full span of 4.5 meters, no internal supporting structure is needed. The foil is held in place by a slight internal overpressure of just 1–3 millibars, which can be maintained by a standard fan. If the pressure temporarily drops—e.g. due to doors being left open—the membrane may briefly sag into the frame. However, since it rarely rains in the Emirates, there‘s no risk of rainwater accumulating in the sagging foil.
To further reduce temperatures, we take advantage of the fact that both winter and nighttime temperatures are significantly lower. We run piping through the adjacent soil, channeling cool outdoor air—especially at night in winter—through the ground. This cools the surrounding soil mass, allowing it to absorb excess heat from the greenhouse during the day.
Above the membrane, a mirrored prism is suspended. This element reflects additional light into the greenhouse during the early morning and late afternoon, when the sun is low in the sky. At midday, when the sun is directly overhead, the prism acts as a shade and reflects part of the sunlight back into the sky. An additional vertical mirror, positioned at a 90° angle to the prism, reflects more sunlight into the greenhouse during winter, when the sun is lower (around 45°), while providing partial shading in the summer.
This setup ensures a nearly constant light intensity throughout both the day and the year—maintaining levels close to the photosynthetic optimum.
The greenhouse is sunk into the ground. This allows the surrounding soil to absorb excess heat during the day. The ideal light intensity for photosynthesis is 15,000 lux, or 250W/m2 of sunlight. However, outside, the intensity is between 100,000 – 150,000 lux, or 1000W/m2, which does not increase photosynthesis but leads to overheating.
Sharja variant:
