The Vertical Forest project aims to build two high-density towers covered by trees, like a forest, within the city of Milan. The two towers will reach respectively 80 meters and 112 meters in height, and they will be able to hold 480 big and medium size trees, 250 small size trees, 11.000 groundcover plants and 5.000 shrubs (the equivalent of a hectare of forest)."In the Bosco Verticale (Vertical Forest), the plant element produces, first and foremost, a change in scale. The project for two residential towers in Porta Nuova area of Milan converts into two large forests climbing up buildings in one of the most densely developed area of the city. Transposing elements of nature into a construction projects and, specifically, onto the membrane of the facade, is a particularly complex operation. The Bosco Verticale represents a first step or degree in this process of hybridization. The building is an enormous scaffolding to be filled, letting the plants climb to the top, colonize every corner, every projection, every free ledge. On the vertical facade, the plants fully accomplish their role of decorating and defining the elevations; more than being forest, the building becomes a gigantic tree. On the urban scale, the observer's eye is caught and impressed by a huge tree, before it notes that the tree is actually composed of individual trees distributed on the facade. […] The facade is alive and changes in intensity and color through the cycles of flowering and the seasons. It responds to atmospheric conditions. Once it has taken form and has adapted forest will cyclically redesign the forms and figures of the facade without any additional help from the architect." (from: Moreno Gentili ed., Barreca & La Varra. Questioni di facciata / A Matter of Facade, 2012)