The Valletta Design Cluster (VDC) is a multifunctional community space and new creative hub located in Valletta, in the restored Old Abattoir (Il-Biċċerija l-Antika). The Old Abattoir was built in the 18th century and has served several uses over the centuries; including as residences, soldiers’ barracks, a manufacturing facility, and a bakery. The works to convert the old building began in 2017 and were completed in 2021, with today’s facility bridging the city’s past to the future.
The goal of the VDC is to provide space and opportunities for Malta’s cultural and creative operators. The space includes co-working spaces, a fully equipped makerspace, meeting and conference rooms, a kitchen, studios on a sustained basis and a new public rooftop garden. Among its other spaces, the VDC also includes two small residences for accommodating visiting professionals.
A garden was built on the roof, a new green lung for the city, open to everyone and accessible by both elevator and stairs. The intervention includes a rooftop pavilion for meetings and workshops, a small pond, a children’s area, seats and tables, two multifunctional outdoor spaces, as well as green spaces with local flora species.
The vegetation selected for this project reflects the typical colours, scents, and characteristics of the Mediterranean scrub. Shrub species resistant to salty winds were used, considering the proximity of the roof garden to the sea. Laurel, lentisk, myrtle and euphorbia were arranged in such a way as to have contrasting seasonal blooms. In addition, typically Maltese tall trees such as olive, carob, frangipani, pomegranate and judas trees have also been selected to provide shaded areas for visitors.
The green roof of the VDC is defined by a system that includes two substrates: a layer of lapillus 10/16 with a thickness that varies from 20 to 50 cm depending on the overlying planting and a second layer composed of real Vulcaflor Intensive cultivation substrate with a thickness varying from 20 to 30 cm. The bottom layer collects moisture from rainfall and irrigation and gradually transfers it by diffusion and capillary action to the growing medium above.
The sub-irrigation system is served by two pumps that collect water from the old cisterns of the Old Abattoir and replenish the artificial aquifer made with mineral substrates. This integration is supported by humidity and rain sensors connected to the control panel of the irrigation system. The disposal of excess rainwater is made through special gutters and drainage pipes integrated with the existing rainwater system.
The focal point of the inner courtyard of the building is the vertical garden that extends from the ground floor to the roof level. This green wall consists of a modular structure fixed to the existing wall through aluminium sections. The irrigation system is characterized by a tubular system and overlapping pots, thanks to which each plant receives the right amount of water by gravity and capillarity. Equipped with humidity and rain sensors, the entire system is activated only when necessary.
The fertilization system combines with the irrigation system and the fertilizer is introduced through adjustable programs depending on the time of day, the season, and the state of need of the plants. The choice of plants is related to the degree of sun exposure and shade in the yard, the location, and ease of maintenance. Among them are potos, tulbaghia, rosemary, spider plant, miseria grass and purple alternatera.
Valletta Design Cluster Green Roof
Location: Valetta, Malta
Architects: TETSUO KONDO ARCHITECTS
Landscape Architect: Doric Studio/Living Walls
Collaborators:
Architects: Frank Muscat, Steve Bonnici, Sergio de Gabriele, Martina Gherardi, Cristina Baronchelli, Chiara Patamia, Stefano Marzo, Karl Camilleri;
Engineers: Anthony Vella, Peter Baldacchino, Stefano Iurato, Julian Micallef
Client: Valletta Cultural Agency