Unlocking the green potential of rooftops

A social enterprise in Spain is helping communities save energy and create community space with green roofs

Spotted: Every building has a roof, and this can be a source of significant energy loss. In a house with no or only minimal insulation, around 25 per cent of the heat produced by the boiler will escape through the roof. Slowing this loss of heat through improvements to the thermal envelope can dramatically reduce energy use – and energy bills. One novel way of achieving this is through the use of a ‘green roof’ – where vegetation is incorporated into a building’s terrace, rooftop, or inner courtyard. According to social enterprise Eixverd, a green roof can save even more energy than an insulated roof.

Eixverd is focused on promoting the sustainability of urban centres through the use of climate change adaptation and mitigation projects. One of its major initiatives is the installation of green roofs on both private and public buildings. The energy advantages of these roofs are extensive. They offer significant absorption of pollutants and CO2, reduce water runoff, promote urban biodiversity, and mitigate the urban heat island effect.

On top of the environmental benefits, Eixverd points out that green roofs require little maintenance and create space for communities to gather and grow their own food while also providing acoustic insulation. One of the green rooftops installed by Eixverd is even watered, in part, using the condensation that forms around rooftop refrigeration units.

While Eixverd offers design and management of green roofs, they do not perform installations or recommend particular suppliers or installers, preferring to “keep all doors open to recommend the most suitable and most economical option to the client”. They add that, “innumerable studies show that a well-functioning green roof provides excellent thermal insulation. In our own experimental green roof, we have observed that, in contrast with the temperatures of up to 60 and 70 degrees Celsius prior to installation, 28 and 35 degrees Celsius are reached under the green roof’s soil.”

While Eixverd is focused on Barcelona, Springwise has spotted several innovations aiming to incorporate plants in buildings around the world. These developments include creating living walls by 3D printing with soil in the US, and a project in the Netherlands that is turning rooftops into kitchen gardens.

Written By: Lisa Magloff