The Diamond Tower (also known as "Diamantone") is a skyscraper located in the business center of Milan, between Viale della Liberazione and Via Galilei . Built as part of the urban regeneration project called "Project Porta Nuova", is 140 meters high, making it the fourth tallest skyscraper in Milan and the fifth highest in Italy. The tower has a faceted shape that resembles a diamond (from which the name derives), and is related to a series of low buildings, called "Diamantini" that arise as an element of continuity of the skyscraper itself. These buildings, like the tower will be used as offices. It is also the tallest steel building in Italy.The design of the master plan of the entire area has been entrusted to the Italian-American Lee Polisano, of the architectural firm Kohn Pedersen Fox, that won an international competition. Polisano was joined by architect Paolo Caputo and engineering company Jacobs for architectural design while the structural design was carried out by Arup. The main feature of the tower is its irregular geometry: perimeter columns of the building are inclined with respect to the vertical axis. The interior layout is characterized by a central core around which the space develops: solution used to maximize the amount of natural light and allow a view of the city. One of the key goals of the Porta Nuova project is to drastically reduce energy consumption by buildings, which will be equipped with the latest energy supply systems based on the use of renewable sources. The Tower Diamond has got the certification "LEED GOLD", one of the highest levels recognized by the Green Building Council for buildings constructed according to the principles of environmental sustainability.The construction officially began January 28, 2010 with the installation of the crane on site and th skyscraper was completed September 14, 2012 . A special feature of the tower is in the use of laminated rather than tempered glass in order to have a more uniform facade and minor defects such as corrugations typical of thermally tempered glass. Another particularity of the tower is the illumination of the tip, which can occur with various colors , for example blue or red.