Design Green Design Madrid's Green Wall Is Flourishing as Is the Caixa Forum By Bonnie Alter Bonnie Alter Writer University of Toronto Bonnie Alter covered the sustainability and design scene for TreeHugger in London and the UK. Learn about our editorial process Updated October 11, 2018 miska michael knapek / Flickr / CC BY-NC 2.0 Share Twitter Pinterest Email Design Tiny Homes Architecture Interior Design Green Design Urban Design Madrid's green wall is a veteran... it was designed by Patrick Blanc, who has created some of the most famous vertical gardens in Europe. It was installed on an exterior wall of a former power station which was renovated by equally famous architects Herzog & de Meuron. The garden and the building have been braving the pollution, hot sun and elements for four years and we are pleased to announce that both mother and child are doing well. First the building: it was a former power plant built in 1899 and one of the few examples of industrial architecture left in the old section of the city. Caixa Forum is a cultural and arts centre that hired Herzog & de Meuron to convert the building and retain the industrial feel. A Swiss firm, they renovated the Tate Modern in London which was formerly a power plant as well. Their master stroke was to remove the base of the building so that it seems to hover over the ground. That created a large plaza which provides a place to sit and meet away from the burning sun. The building goes underground, for an auditorium, and three stories above with gallery space, shop and cafe. The rusted iron cladding on the top level has aged and corroded and is a warm bronze colour. The vertical garden, designed by Patrick Blanc, is 4 storeys high and takes up one outside wall, overlooking the plaza. It has 15,000 plants from more than 250 different species and most of it is flourishing. There is an irrigation system which seems to be ongoing, given the gentle mist of droplets that emanates from the garden. The architects said that they wanted to "create a very unusual encounter between the rough and the natural, ...to incorporate nature so there can be the smell of a garden where you would not expect it." The building, and garden are in the cultural quarter where the other famous museums are located. Caixa Forum has become an urban oasis in contrast to the more formal, and much older, buildings in the vicinity.