A research programme conducted by Gabriel Perez in partnership with Universitat Politecnica de Catalunya, BarcelonaTech (UCP) and the University of Lleida (UdL) has established that using green facades in buildings could result in substantial energy savings.
Traditionally, plants have been used in architecture only for ornamental decoration or to perform ecological functions like reducing the consumption of energy. However the use of plants poses many difficulties for users like the change in the shape, weight, form and capacity of plants and the amount of time and investment involved in installation and maintenance of such plants. Another concern is the damage they might cause to buildings.
To provide solutions to these issues Gabriel Perez suggests that green facades could be more useful and convenient as compared to living walls. While green facades are formed on light materials such as meshes, metal trellises and cable systems, living walls are walls that are covered with plants totally. Though living walls are great as ornamental decorations, they are not useful to the environment, consume more space and need more time for maintenance. The costs of maintaining living walls are also high. Green facades are more convenient as the façade is separated from the walls and forms a sort of a curtain. This can be very effective in preventing solar radiation from affecting the building and at the same time is easy to maintain and occupies lesser space. They not only provide a cool environment but also act as a thermal insulation layer for the building.
Source: http://www.upc.edu