Green facades could offer many advantages for Smart Cities. Green facades add to the thermal insulation behaviour of buildings, to the biodiversity in the city, the quality of public space and reduction of air pollution; fine dust and carbondioxide. This adds to the idea of the ‘healthy city’. There are two types of green facades. Living wall systems and walls which consist of creepers or hanging plants. The first is an irrigated system of growing panels in which plants literally grow. The latter is a facade or a mesh along which creepers of hanging plants can grow. In north western Europe most green facades have a webbased irrigation system which monitors climate conditions in order to coordinate irrigation. With temperatures below zero degrees Celsius the irrigation system empties itself.