The Green Ark in the Botanical Garden of Meise

The new conservatory at the heart of Meise Botanical Garden has doubled in size and houses a living collection of plant species from climates around the world. An innovative addition the Green Ark opens this otherwise closed collection to the public, offering visitors a rare glimpse behind the scenes, unique worldwide. Inspired by the formal logic of a cactus skeleton, the design translates botanical principles into architecture. We explored how the form and natural properties of wood could merge into a striking spatial structure topped with a roof terrace that serves as an elevated viewpoint.

Guided by the Botanical Garden’s ambition to be climate-neutral by 2045, an energy-efficient design was essential. The new greenhouses feature 4 temperature zones and provide optimal spatial and technical conditions for maintaining a living collection. The warmest zones are placed at the heart, while the surrounding cooler areas are fitted with insulating polycarbonate panels or double glazing. Combined with shading and thermal screens, this results in an energy-efficient complex with 50% less energy-use than before. Rainwater is collected in underground reservoirs, allowing them to bridge several weeks of drought. Because the collection is so fragile, it is normally closed to visitors. A carefully designed route guides the public deep into the greenhouse complex to the visitor pavilion, offering unique insight into the work of the researchers and the collections. The route continues into the service building and seed bank, connecting visitors closely to the Garden’s mission and work.

In its material expression, the wooden pavilion contrasts with the steel-and-glass greenhouse structure. Exploring the boundaries of timber construction and inspired by the skeleton of a cactus, the design features a spatial wooden roof based on the principles of a hyperbolic paraboloid; a ruled surface where straight planks are layered in two directions to form a graceful double curvature. At the gable ends, the roof follows a parabolic line, creating a distinctive double-curved form that remains fully visible from within. The roof is clad with wooden shingles made from leftover material of a fast-growing, renewable resource, treated to achieve class A1 performance. Resting on a concrete base that continues the architectural language of the entrance buildings, the pavilion includes a public roof terrace offering a new vantage point into the greenhouses. The public space accommodates exhibitions, lectures, and other events, engaging visitors in the mission of the Botanical Garden.