Bosco Verticale. Photo courtesy Stefano Boeri Architetti
Project Information
Bosco Verticale (Vertical Forest) is a pair of residential towers in the Porta Nuova district of Milan, Italy, between Via Gaetano de Castillia and Via Federico Confalonieri near Milano Porta Garibaldi railway station. They have a height of 111 metres (364 ft) and 76 metres (249 ft) and contain more than 900 trees (approximately 550 and 350 in the first and second towers, respectively) on 8,900 square metres (96,000 sq ft) of terraces. Within the complex is an 11-storey office building; its facade does not include plants.
The towers were designed by Boeri Studio (Stefano Boeri, Gianandrea Barreca and Giovanni La Varra). It also involved input from horticulturalists and botanists.
The project was designed as part of the rehabilitation of the historic district of Milan between Via De Castillia and Confalonieri in Porta Nuova, which is known to be the richest business district in Europe. Bosco Verticale is one of the biggest European redevelopment projects, consisting of two residential towers of which the largest is 26 floors and 110 metres high (called Torre E) and the smaller tower is 18 floors and 76 metres high (called Torre D). It contains 400 condominium units priced from 3,000–12,000 Euro per square metre.
According to Stefano Boeri, the building was inspired by Italo Calvino's 1957 novel The Baron in the Trees, in which the protagonist decides to abandon the ground and live on the trees for the rest of his life. The project was named Bosco Verticale, or in English "Vertical Forest", because each tower houses 900 trees, 5,000 shrubs and 11,000 perennial plants, which help mitigate smog and produce oxygen. These tree-packed high rises help cities built for density, adding more housing and infrastructure, while improving the air quality. Trees and plants are the most efficient and cost effective way to absorb carbon dioxide. The 20,000 trees and perennial plants in the buildings will convert approximately 44,000 pounds of carbon each year.[7] With more than 90 species, the buildings' biodiversity is expected to attract new bird and insect species to the city. It is also used to moderate temperatures in the building in the winter and summer, by shading the interiors from the sun and blocking harsh winds. The vegetation also protects the interior spaces from noise pollution and dust from street-level traffic.
Bosco Verticale, Milan. Photo courtesy Stefano Boeri Architetti.
The building itself is self-sufficient by using renewable energy from solar panels and filtered waste water to sustain the buildings' plant life. These green technology systems reduce the overall waste and carbon footprint of the towers. Lead designer Stefano Boeri stated, “It’s very important to completely change how these new cities are developing. Urban forestation is one of the biggest issues for me in that context. That means parks, it means gardens, but it also means having buildings with trees.”
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 are designed to be 28 cm thick, with 1.30 metre parapets. Bosco Verticale is the first model of urban densification of nature in a city and Boeri plans to build similar structures in Switzerland, the Netherlands (one is already under construction in Utrecht), and multiple cities in China.
The Porta Nova project, which includes the Bosco Verticale, is a city plan (2004) to transform the urban neighbourhood (Porta Nova) into a business-residential district implementing green solutions. It is an investment totalling more than EUR 2 billion. The Vertical Forest consists of two residential towers 110 and 76 m high hosting 900 trees (each measuring 3, 6 or 9 metres) and over 20 000 plants (a wide range of shrubs and floral plants) distributed according to the sun exposure of the facade. It is estimated that the ecosystem services from the plants in the two towers (CO2 storage, air quality, biodiversity improvement) are equal to the services of 2 ha of forest (European Conference, 2014).
An experimental campaign (Buffoni A. et al., 2013) demonstrated that the vegetation in the towers was capable of reducing particulate concentration. The percentage of average abatement, due to the plants, ranged from about 30 % to 20 % for PM10 (Particular Matter) and TSP (Total Suspended Particulate) respectively. These results confirm the effective potential of trees and green barriers (shrubs and hedges) in removing airborne particulate matter. These are common features of urban forests and pocket parks, which improve the urban environment and life quality of local residents and confirm the need to preserve and increase urban vegetation (Buffoni A. et al., 2013).
Bosco Verticale, Milan. Photo courtesy Stefano Boeri Architetti
Objective
Urban redevelopment was an opportunity to adopt solutions and achieve different targets through nature-based solutions. Carta of Milan, the city's strategic environmental plan, recognises ‘green infrastructure’ as the best way to achieve environmental targets, promote social development and improve social welfare. On a wider scale, the Lombardy Region manages the green infrastructure actions for ecological connections and the creation of ecosystems, ensuring continuity between the Alps and the Po Valley (Pianura Padana) and the urban environments within that area, ensured by the Rete Ecologica Regionale Plan. The plan provides guidelines to the different municipalities for the management and creation of ecosystems and outlines the funding mechanisms. Gorla Maggiore, about 30 kilometres northwest of Milan, lies in a delicate transition zone. The town and its waterpark help to improve the quality of the area's water and to better regulate the flow of water.
Challenges
Abandoned areas in the metropolitan area of Milan, whose population is over 4.1 million (2014 OECD), have been redeveloped. This has been an opportunity to implement green solutions when regenerating entire districts. Milan also needs to deal with traffic pollution resulting from the increased urbanisation of recent years; it poses a significant risk to human health and well-being. Reducing soil consumption is also a major challenge for Milan. More than 60 % of the soil is sealed, one of the highest levels in Italy.
Bosco Verticale, Milan. Photo courtesy Studio Laura Gatti.
Impacts
The Porta Nova project, which includes the Bosco Verticale, is a city plan (2004) to transform the urban neighbourhood (Porta Nova) into a business-residential district implementing green solutions. It is an investment totalling more than EUR 2 billion. The Vertical Forest consists of two residential towers 110 and 76 m high hosting 900 trees (each measuring 3, 6 or 9 metres) and over 20 000 plants (a wide range of shrubs and floral plants) distributed according to the sun exposure of the facade. It is estimated that the ecosystem services from the plants in the two towers (CO2 storage, air quality, biodiversity improvement) are equal to the services of 2 ha of forest (European Conference, 2014).
An experimental campaign (Buffoni A. et al., 2013) demonstrated that the vegetation in the towers was capable of reducing particulate concentration. The percentage of average abatement, due to the plants, ranged from about 30 % to 20 % for PM10 (Particular Matter) and TSP (Total Suspended Particulate) respectively. These results confirm the effective potential of trees and green barriers (shrubs and hedges) in removing airborne particulate matter. These are common features of urban forests and pocket parks, which improve the urban environment and life quality of local residents and confirm the need to preserve and increase urban vegetation (Buffoni A. et al., 2013).
Reference: