Study on Bosco Verticale and Future Urban Reforestation
By: Qixuan Ren
Tags: Vertical Forest, Sustainable Development, Urban Planning, Urban Revolution

What is Bosco Verticale?

Bosco Verticale, is Boeri Studio’s project, with two residential buildings located in the dense commercial district of Milan, Italy. Two buildings have taken themselves as a brand-new design like a novel landmark and a milestone, which injects new vitality into both the Milan city and the entire urban architectural design at the same time. The green facade of the Bosco Verticale created “Treescrapers” for the city skyline, and this feature can resolve noise, air quality, shading for cooling, and other issues, while also embracing aesthetics.

“More than 94% of tall buildings are clad with glass, so we started thinking about these skins, metal, ceramics, and other materials that ‘mineralize’ the urban surfaces.” — Stefano Boeri

Site map

What and How did the green facade form?

The green facade of Bosco Verticale, as the most iconic and important feature for sustainability, has been planned carefully and thoughtfully. The benefits of the plants are variable, and it highly depends on the positioning of the vegetation. The size and the thickness of the plants and also the leaf characteristics of each species would affect the final results.

In order to make the Green Facade live and benefit the building, the methodology that monitoring the trees has been applied to the site. The monitoring data provides information to determine if plants are in good health, or if they suffer from some deficit that can negatively affect their physiology. Trees were selected for test on the different heights and areas of the selected building to evaluate the growth and performance.

Trees selected for the monitoring program in Oct 2013 (CTBUH Report)

After two years of monitoring, the general condition of the trees was good and ready for the next step. Different species of trees, shrubs, and perennial plants have eventually being planted at the planter outside the building.

From the date this building was planned for the completion of the construction, seven years have passed, the two shiny green towers with living green envelopes have rises in Milan’s skyline. The green coverage is relatively dense. In plan view, the vegetation is about 2.3–3.1 meters from the exterior wall and covers over 50% of the floor perimeter. In the elevation calculation, the green coverage is around 40% (Wood, 2014).

“Sustainability without biodiversity is ‘mechanical sustainability….I started to think about this visionary project to see if a tall building could become a ‘medium’ for ecosystems. ” Boeri

Section view of Bosco Verticale

What does the green facade do?

The green facade of Bosco Verticale also exists as a regulator of the urban microclimate. The overall vegetations planted on the buildings are over 900 trees, 5,000 shrubs, and 11,000 perennial plants, which will have an unimaginable regulating effect on temperature, oxygen emission, and humidity. The research report in Vertical Greenery claims that plants can act as a sunscreen, windscreen, and solar energy transmitter inside the overall internal environment. Urban Forestry’s research survey shows that every year, the buildings will absorb 30 tons of carbon dioxide and produce 19 tons of oxygen, which emissions can be comparable to 215,000 square feet of forestland. Plants can also absorb dust particles in the air passing through the building. It is mentioned in an article by CA Aggie Group that these buildings are therefore called the “green lungs” of the city for their functions as filters. Humans are not just the only users of Bosco Verticale. In addition to about 100 different plant species, including 15 species of trees, 45 shrubs and 34 types of perennials make their homes in the buildings. These plants also provide a nesting and living environment for more than 20 species of birds and uncounted insects, forming a wonderful phenomenon of harmonious coexistence between the high-tech city and nature.

What is the echo from the industry?

Bosco Verticlae wins many awards in architectural designs.

-Best Tall Building in Europe by the Council on Tall Building and Urban Habitat 2014

-International Highrise Award (IHP) 2014 for the world’s most innovative high-rise building by the City of Frankfurt am Main together with Deutsches Architektur museum and Deka Bank

-International Highrise Award 2014 for the world’s most innovative high-rise

-Best Tall Building Worldwide 2015 by the CTBUH in Chicago

Especially the final one, “2015 Best Tall Building Worldwide” at the 14th Annual CTBUH International Best Tall Building Awards Symposium, which surpassed the judges for the other three selected works and finally won the global championship. (CTBUH, 2015)

Our group follows the LEED rating system to give a score on Bosco Verticale, and the final result is similar to how it certified by officials: it received 75 points out of 110 from us and can be confirmed as a Gold LEED project.

LEED Rating from our study group: Result is 75 out of 110

Who are the designers and what do they say?

Members of Stefano Boeri Architetti

SBA, also known as Stefano Boeri his Studio, participated in the majority of proposed concept establishment and designs of Milan’s Bosco Verticale. From 1993 till now, Boeri’s studio engages in research and practice in the architecture and urbanism fields and also becomes part of the urban redevelopment designers that include both landscape and cultural designs diversification. Bosco Verticale is one of their most successful works, but also an exhibit of their implementation on one main concept that: architects have the duty to launch a global campaign on urban forestry to multiply the presence of forests and trees in our cities for the final objectives that reverse climate change, protect existing natural species, and enhance a greener, healthier and more pleasant living environment for humans. (Stefano Boeri Architetti) Present every tall building as a tree, and “planting” every city as a forest. An idea that is considered innovative and astonishing, but actually reveals its possible future by this group of passionate people.

At the same time Boeri’s Studio claims for the priority of urban forestry in globalizing governmental cognition in city designs, they participate in the actual creation and implementation of this concept by turning those green buildings and sites into real places in use.

How would the urban forest grow?

Bosco Verticale is the first vertical forest designed by SBA, and it is a starting sign. The concept of urban forestry has been applied to large amounts of instances. You can find their existence in world-spread SBA projects.

Bosco Verticale, SBA

Verticale Forest in Cario, SBA

The vertical forest on the top is Tirana Vertical Forest, the middle one is Cairo Vertical Forest, and the bottom one is Nanjing Vertical Forest, all use the same planting, construction, and irrigation technologies that have been developed and proved feasible in Bosco Verticale. Plants on the exterior wall and balconies play significant roles in CO² absorbing, air purification, air humidifier, temperature regulator, and so on.

One really interesting point is, all those vertical forests have their different building uses due to the difference in locations, which reflect the various cultures and backgrounds of different countries. This also implies that even in all kinds of environments, the concept of urban forestry can still be interpreted and contributed to green tall buildings development.

Urban Jungle, SBA

Italy’s Prato Urban Jungle, designed with the main purpose of co-living between human and natural species and re-naturalization. Like Bosco Verticale’s effectiveness, the vegetation cover in these buildings achieves real green colonization and meanwhile providing solutions for sunlight exposure, air quality, moisture, temperature, and noise problems. As a result, the urban jungle successfully creates a green and healthy environment for its users.

Space utilities on this site according to the SBA website:

-Transformation of the unused roof into a green roof, making it an island of biodiversity, usable by employees as a place for socializing, for small events or physical activity

-Creation of a large entrance pergola that welcomes the inhabitants and creates a green connection with the greenhouse — designed by Pnat — and the garden

-Transformation of the ground floor and the existing car park into a social garden, as a place accessible by the residences’ inhabitants

etc.

Ca’ delle Alzaie, SBA

Ca’ delle Alzaie, three class A residential buildings with private gardens located in Treviso, Italy, near the historic center. The site uses continuous terraces along the riverbank to create vertical elements for plant nursery places. Linear overhanging pots and vases for small and medium-sized shrubs are placed on the north side of the building, and the medium and large ones are planted on the south side. Plants will change colors when seasons alternate, which creates a splendid visual outcome.

Palazzo Verde, SBA

The Palazzo Verde is located in Antwerp, Belgium. One of its main design purposes is to improve the overall surrounding urban ecological environment and create a city greenification landmark. Tree function of absorbing CO² and producing oxygen, also doing great on regulating the general high-density population cities’ air problems. The platform of man-made forests can also act as homes for natural species that live in cities but are struggling with habitat problems.

Tirana Riverside, SBA

SBA designed Tirana Riverside with the cooperation of SON-Group.

It is located along the northern border of the Albanian capital close to the Tirana river and acts as a large public area that provides self-sufficient clean energy, water, food, and urban public services. Domestic greenery designs are shown in open ground lands, rooftops, and many common living spaces, and play a distinctive role in mitigating the urban heat island effect.

Cancun Smart Forest City, SBA

Cancun Smart Forest City, a new planning forestry urban district in Mexico.

The entire forest city is designed as one hundred percent of energy production self-sufficient. Most of its energy will come from a perimeter ring of photovoltaic panels, also together with an underground water system connected to the sea for irrigation purposes. Additionally, the city only allows electric and semi-automatic vehicles inside, which means that transportation will exist in a green style.

Are there any further improvements for Bosco Verticale?

Part of sustainable development includes equity and meeting the social demands of a region. Bosco Verticale is unattainable to the majority of Milan residents, the starting price for an apartment unit is 2 million euros which translates to about 2.4 million dollars. In Italy, the average income is 2,500 euros a month. As the second-largest city, Milan is facing a lack of affordable housing; Vertical Forest’s government investment was part of an urban renewal redevelopment of the Porta Nuova district to increase residential and commercial areas. Going back to planning, design process, and construction a possible solution to making Bosco Verticale more affordable would be to increase density and reduce square meters of each apartment. There are only 113 apartments, each has about 160 indoor sqm and 60 outdoor sqm. Increasing density would create more housing opportunities, and there should also be an affordable housing program.

Resources

Brent Lunds. Sustainability in the Built Environment: Bosco Verticale — The Skyscraper with 600 Trees, The California Aggie, 2015

Giacomello, Elena, and Massimo Valagussa. Vertical Greenery: Evaluating the High-Rise Vegetation of the Bosco Verticale, Milan. Published in conjunction with the Council on Tall Buildings and Urban Habitat (CTBUH), Arup, and Università Iuav Di Venezia, 2015.

Land. “Porta Nuova — Milan, Italy.” LAND , LAND Italia, 13 Feb. 2020,

Scheuermann, Rudi. “Increased High-Rise Resilience to Stabilize Cities of the Future.” Increased High-Rise Resilience to Stabilize Cities of the Future, CTBUH’s Research Paper, 2016.

The Skyscraper Center, Global Tall Building Database of the CTBUH

Wood, A., Bahrami, P. & Safarik, D.Green Walls in High-Rise Building. 2014