Eversheds Ltd, 1 Wood St., London EC2V 7WS
Design/Specification: Green Roof Consultancy Ltd
Green roof System: Skygardens
Substrates/Growing Media: Shire Green Roof Substrates Ltd
Native Wildflowers: British Wildflowers
Native seeds: Emorsgate Ltd
Originally installed as a simple sedum blanket/mat system, the clients wanted to maximise the green roof for biodiversity. The Green Roof Consultancy was commissioned, not only to design in green roof elements for biodiversity, but also other features for nature conservation.
The initial system consisted of an inverted roof with with insulation on top of the waterproofing element. A sponge element acts as a drainage and protection layer. A green roof substrate, at depth of 20mm was then laid onto the drainage layer and a 20mm blanket, consisting of a range of sedum species was laid out. This not only covered the main roof but was one of the first to be installed beneath window cleaning runners around the perimeter of the roof.
Seminal research in London and Switzerland has demonstrated that invertebrate biodiversity can be increased on a green roof by producing greater topographic variety and ensuring a range of native wildflowers are planted or seeded onto the roof.
The Green Roof Consultancy provided a design to retro-fit elements in keeping with the research (soon to be published as Guidelines for Green Roofs and Invertebrate Biodiversity. These included:
• A series of mounds with a maximum height of 150mm above the sedum blanket using Shire Green Roof substrates
• Creation of wood/log elements across the roof
• The use of dried wildflower hay bundles
• Seeding of new substrate areas sand mounds with a native seed mix
The roof also has a series of bird boxes, including boxes for House Martins, Peregrines, Swifts and Black redstarts.
Since the installation staff at Eversheds have installed an area for food growing. This is a top of a shingle area set aside for new industrial plant. There are also two bee hives on the roof. Many hives have been installed on roofs throughout London but this is one of the only situations where the hives are besides flower rich habitat, an important consideration.