Edinburgh-based architecture practice Smith Scott Mullan Associates have created the first new glasshouse to be built in the Royal Botanic Garden Edinburgh for over thirty years and the only one in Britain dedicated to growing alpine plants in a tufa rockscape.
The key design drivers for Smith Scott Mullan Associates were to respond to the cold, windy yet bright, mountain environments required by these plants, while providing a distinctive structure that will act as a contemporary landmark in its own right.
The galvanized steel and glass structure modifies the microclimate by providing shelter from excessive rain while transmitting maximum light and increasing wind speed at plant level. The visual concept evokes the nature of plants opening to the sun, while reflecting both the strength of the mountains and the sharp edges of frost shattered rock, prevalent in alpine settings.
The architects worked closely with the Garden’s horticultural staff to understand and respond to the plants’ exacting requirements. The plants are grown in a porous rock called tufa which is formed from calcium carbonate deposited from springs. The north face of the building is a cavity wall faced with the tufa rock and filled with compost material, which has an automatic watering system. This vertical arrangement allows visitors a close-up view of the small and delicate plants.
The central steel support of the glazed roof acts as a rainwater harvester gathering water in a large underground tank with pumps to provide irrigation to the plants within the Alpine House and throughout the garden.
Galvanized steel was selected as the primary material for the project to ensure longevity for the building, enable the structure and its junctions to be expressed and provide a cost effective solution to deliver the design concept and technical requirements. The structure, glazing and framing is entirely recyclable, adding to the sustainable agenda set as part of the brief.
The structural design includes a dramatic 8 m cantilever formed in tapering steel beams creating a canopy over the main entrance to the glasshouse. The primary structural steel elements were prefabricated and pre-assembled for testing, before being galvanized and brought to site for final erection.
Once the steel and glass structure was complete on site the landscaping work was carried out by the garden’s own horticultural team.