Vertical forest

‘Vertical Forest is the project of two residential towers designed as part of the rehabilitation of the historic district of “Porta Nuova” in Milano, near “Porta Garibaldi” railway station. It consists of two residential towers of which the largest is 26 floors and 119 meters high (called Tower E) and the smaller is 18 floors and 87 meters high (called Tower D). It will contain 400 condominium units priced from 3,000 Euro per square metre and higher and will host more than 900 trees (approximately 550 and 350 trees in the first and second towers) on 8,900 square metres (96,000 sq ft) of terraces. The structure was completed in the first quarter 2012 and the project is currently proceeding with the construction of facades and facilities. The towers were designed by architects Stefano Boeri, Gianandrea Barreca and Giovanni La Varra. It also involved input from horticulturalists and botanists.’


‘It’s called Vertical Forest because each tower will house trees between three and six meters which will help mitigate smog and produce oxygen. It is also used to moderate temperatures in the building in the winter and summer. The plants also attenuate noise. The design was tested in a wind tunnel to ensure the trees would not topple from gusts of wind. Botanists and horticulturalists were consulted by the engineering team to ensure that the structure could bear the load imposed by the plants. The steel-reinforced concrete balconies were designed to be 28 cm thick, with 1.30 metre parapets. Boeri anticipated a 5% increase to construction costs for the additional structure required to support the plants. Completition is expected by end of 2013.’

‘The construction of the towers began in late 2009 and early 2010, involving 6,000 onsite construction workers. Between mid-2010 and early 2011 construction progressed very slowly and the towers rose by only five floors while the core rose to the seventh floor. Construction progressed throughout 2011, and by the beginning of 2012 the structures were completed, and construction of the facades and installation of the plants began. On 11 April 2012, one of the buildings was used as a temporary art gallery and opened to the public for an art exhibition hosted during Milano Fashion Week. Installation of plants began on 13 June 2012. When complete, the two buildings will have 730 plants (480 large, 250 small), 5,000 shrubs and 11,000 perennials and groundcover on its facades. The original design had specified 1,280 tall plants and 920 short plants encompassing 50 species. Overall, the vegetation is the equivalent of that found in a one hectare woodlot.’