RIBA Awards for International Excellence 2018 / RIBA International Emerging Architect 2018

The Vertical Forest project aims to build high-density tower blocks with trees within the city. The first example of a Vertical Forest is currently under construction in the Garibaldi Repubblica area in Milan, with two towers which are 80 metres and 112 metres tall respectively, and which 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). The Vertical Forest has at its heart an concept of architecture which demineralises urban areas and uses the changing shape and form of leaves for its
facades, and thus which hands over to vegetation itself the task of absorbing the dust in the air, and of creating an adequate micro-climate in order to filter out the sunlight. This is a kind of biological architecture which refuses to adopt a strictly technological and mechanical approach to environmental sustainability.

biological habitats
Vertical Forest increases biodiversity. It helps to set up an urban ecosystem where different kinds of vegetation create a vertical environment which can also be colonised by birds and insects, and thus becomes both a magnet for and a symbol of the spontaneous recolonisation of the city by vegetation and by animal life. The creation of a number of vertical forests in the city will be able to create a network of environmental corridors which will give life to the main parks in the city, bringing the green space of avenues and gardens and connecting various spaces of spontaneous vegetation growth.

mitigations
Vertical Forest helps to build a micro-climate and to filter dust particles which are present in the urban environment. The diversity of the plants helps to create humidity, and absorb CO2 and dust, produces oxygen, protects people and houses from the suns rays and from acoustic pollution.

anti-sprawl
Vertical Forest is an anti-sprawl measure which aims to control and reduce urban expansion. If we think of them in terms of urban densification, each tower of the Vertical Forest is equivalent to an area of urban sprawl of family houses and buildings of up to 50,000 square metres.

trees
are a key element in understanding architectural projects and garden systems. In this case the choice of the types of trees was made to fit with their positioning on the facades and in terms of their height, and took two years to conclude alongside a group of botanists. The plants used in this project will be grown specifically for this purpose and will be pre-cultivated. Over this period these plants slowly got used to the conditions they will be placed in on the building.

ecology billboards
Vertical Forest is a landmark in the city which is able to release new kinds of variable landscapes which can change their form in each season depending on the types of plants involved. The vertical forests will offer a changing view of the metropolitan city below.

management
the management of the trees' pots is under building regulation, as well as the upkeep of the greenery and the number of plants for each pot.

irrigation
in order to understand the need for water the plan for these buildings took into account the distribution of plants across various floors and their positioning.



CREDITS Architectural project

Boeri Studio (Stefano Boeri, Gianandrea Barreca, Giovanni La Varra)
Bosco Verticale Landscape Design: Emanuela Borio and Laura Gatti

Supervision of works: Francesco de Felice, Davor Popovic
Design development: Gianni Bertoldi (coordinator), Alessandro Agosti, Andrea Casetto,
Matteo Colognese, Angela Parrozzani, Stefano Onnis
Schematic design and PII: Frederic de Smet (coordinator), Daniele Barillari, Marco Brega,
Julien Boitard, Matilde Cassani, Andrea Casetto, Francesca Cesa Bianchi, Inge Lengwenus,
Corrado Longa, Eleanna Kotsikou, Matteo Marzi, Emanuela Messina, Andrea Sellanes

Design fases: 2006 – 2008
Construction fases: 2008 – 2013

Detailed green design: Emanuela Borio e Laura Gatti
Structures: Arup Italia s.r.l. | Holzner & Bertagnolli Engineering srl
Facilities design: Hilson Moran Italia s.p.a.
Detailed design: Tekne s.p.a.
Open Space Design: Land s.r.l.
Infrastructure design: Alpina s.p.a.
Contract administration (DL): MI.PR.AV. s.r.l.

Milan’s Il Bosco Verticale (the Vertical Forest) is a new approach to high rise buildings in which trees and humans co-exist. In essence it is an architectural concept which replaces traditional materials on urban surfaces using the changing polychromy of leaves for its walls. The project consists of two towers of 80m and 112m, planted with almost 17,000 trees, shrubs and plants. This provides the equivalent greenery –over an urban surface of 1,500m² - of 20,000m² of forest and undergrowth.

This is an approach that contributes to the regeneration of the environment and urban biodiversity, without expanding the territory of the city. Compared to many other superficial tokenistic ‘green towers’ this is an impressive experiment and deserves to exert influence over the development of tower design in the future.

The towers replaced an old industrial building once occupied by artists and are part of a wider, incomplete, masterplan. While they in part seem anti urban - a vestige of the Corbusian Ville Radieuse ideal– they do allow park space to be created in addition to the substantial vertical bio-diversity gained.

One can’t but admire the impact of the mature greenery as a beacon of Milan’s seasons whilst offering verdant balconies as substantial amenities to individual apartments.

Arriving at the right selection of vegetation took years of testing. Plants had two years of observation to determine which were most resilient for the conditions. Species and specific strains were chosen not only based on the climate and sun conditions but also in their ability to resist simulated wind tunnel test. The size of the trees is controlled by the volumetric dimensions of the planter base thus only plants needed to be able to survive the constrictive bases. From the plants tested during the two-year period only the strongest 80% were then planted.